Communication method, core network node, and wireless device

ABSTRACT

It is intended to solve or at least reduce such a problem that a UE cannot know that a network is abnormal. A wireless terminal in an aspect of the present disclosure includes: a communication unit ( 11 ) configured to receive a registration permission message including at least one piece of information indicating that the procedure of first network slice-specific authentication and authorization is pending; and a control unit ( 12 ) configured to activate, upon the reception of the registration permission message, a timer for determining that the procedure of network slice-specific authentication and authorization is abnormal.

TECHNICAL FIELD

The present disclosure relates to a communication method, a core networknode, and a wireless device.

BACKGROUND ART

A new generation network called the fifth generation (5G) network hasbeen researched in telecommunication industries. Actions have beenstarted at a plurality of research standardization organizations todevelop the 5G network, which provides services to a plurality ofvertical service providers and provides services to various kinds ofterminals. In particular, the 3rd Generation Partnership Project (3GPP)has been discussing next-generation communication technologies andsystem architecture of the 5G network as a next-generation mobilecommunication system. In particular, the 3GPP proceeds specification ofa 5G system (5GS) as a system that achieves a 5G mobile communicationsystem. The 5GS specification is disclosed in, for example, Non PatentLiterature 1, Non Patent Literature 2, and Non Patent Literature 3.

For example, specification of a network slicing technology has been madeas one main characteristic of the 5GS.

A network slice is a collection of logical network functions andresources that achieve a communication service in a particular use case.Network slicing is processing that divides one physical network into aplurality of slices.

Non Patent Literature 1 discloses processing in which a wireless device(user equipment (UE)) uses single network slice selection assistanceinformation (S-NSSAI).

S-NSSAI may be configured with a slice/service type (SST) and a slicedifferentiator (SD). Alternatively, S-NSSAI may be configured only withthe SST. Note that the SST may indicate functions or services of anetwork slice, and the SD may be complemental information used toidentify network slices indicated by the same SST.

A network slice instance is an instance of a network slice having acontrol plane (c-plane (cp)) function and a user plane (u-plane (up))function, which is disclosed in Non Patent Literature 1.

As for the relation between S-NSSAI and a network slice instance, aplurality of different pieces of S-NSSAI may be associated with onenetwork slice instance. Moreover, one piece of S-NSSAI may be associatedwith one network slice instance or may be associated with a plurality ofdifferent network slice instances. A network selects an appropriatenetwork slice instance by using S-NSSAI and the like. A function toselect a network slice instance is described in Section 5.15 of NonPatent Literature 1. The selected network slice instance provides anetwork slice-specific service to a UE.

Network slice selection assistance information (NSSAI) is a collectionof pieces of S-NSSAI. NSSAI has five NSSAI aspects, namely, configuredNSSAI, rejected NSSAI, allowed NSSAI, requested NSSAI, and subscribedNSSAI.

Requested NSSAI includes one or more pieces of S-NSSAI that the UEtransfers to the network. Allowed NSSAI includes one or more piece ofS-NSSAI that the network permits to be used. Rejected NSSAI includesS-NSSAI that the network rejects to be used, and each S-NSSAI includedin rejected NSSAI is associated with a reason value (cause value).Configured NSSAI includes one or more pieces of S-NSSAI that areapplicable to one or more public land mobile networks (PLMN), which isindicated to the UE. Subscribed NSSAI includes S-NSSAI based onsubscriber information that the UE subscribes to use a PLMN.

The 3GPP has been also discussing a network slice-specificauthentication and authorization function. The procedure of networkslice-specific authentication and authorization is described in detailin Section 5.15 of Non Patent Literature 1. As disclosed in Non PatentLiterature 1, the network activates the procedure of networkslice-specific authentication and authorization, and finally notifiesthe UE of a result of network slice-specific authentication andauthorization.

CITATION LIST Non Patent Literature

-   Non Patent Literature 1: 3GPP TS 23.501 V16.1.0 (2019-06)-   Non Patent Literature 2: 3GPP TS 23.502 V16.1.1 (2019-06)-   Non Patent Literature 3: 3GPP TS 24.501 V16.1.0 (2019-06)

SUMMARY OF INVENTION Technical Problem

The 3GPP has been discussing the network slice-specific authenticationand authorization function. However, processing of operating a userequipment (UE) and a network when the network becomes abnormal while theprocedure of network slice-specific authentication and authorization isperformed is not clarified. Note that the state of being abnormal may bea state in which execution of the procedure of network slice-specificauthentication and authorization is activated but the execution of theprocedure is delayed. Alternatively, the state of being abnormal may bea state in which execution of the procedure of network slice-specificauthentication and authorization is activated but signals betweendevices necessary for the procedure are lost. Alternatively, the stateof being abnormal may be a state in which execution of the procedure ofnetwork slice-specific authentication and authorization is needed butnot activated.

In this case, the network has no means of notifying the UE of theabnormal state of the network, and thus the UE cannot know that thenetwork has become abnormal. Accordingly, for example, such a problempotentially occurs that the UE indefinitely waits a notification ofstart and/or completion of the procedure of network slice-specificauthentication and authorization from the network. Thus, the UE and thenetwork, which are compatible with the network slice-specificauthentication and authorization procedure function, cannot provideservices using the network slice-specific authentication andauthorization function.

The present disclosure is made in view of such a situation and intendedto solve or at least reduce such a problem that a UE cannot know that anetwork is abnormal.

Solution to Problem

A wireless terminal in an aspect of the present disclosure includes: acommunication unit configured to receive a registration permissionmessage including at least one piece of information indicating that aprocedure of first network slice-specific authentication andauthorization is pending; and a control unit configured to activate,upon the reception of the registration permission message, a timer fordetermining that the procedure of network slice-specific authenticationand authorization is abnormal.

A core network node in another aspect of the present disclosureincludes: a communication unit configured to transmit, to a wirelessterminal, a registration permission message including at least one pieceof information indicating that a procedure of first networkslice-specific authentication and authorization is pending; and acontrol unit configured to activate, upon the transmission of theregistration permission message, a timer for determining that theprocedure of network slice-specific authentication and authorization isabnormal.

Advantageous Effects of Invention

According to the present disclosure, a UE can know that a network isabnormal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration schematic diagram of a UE according to eachaspect.

FIG. 2 is a configuration schematic diagram of an AMF according to eachaspect.

FIG. 3 is a configuration diagram of the UE according to each aspect.

FIG. 4 is a configuration diagram of the AMF according to each aspect.

FIG. 5 is a diagram illustrating an initial procedure as the premise ofeach aspect.

FIG. 6 is a diagram illustrating a network slice-specific authenticationand authorization procedure according to each aspect.

FIG. 7 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to a first aspect.

FIG. 8 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to the first aspect.

FIG. 9 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to the first aspect.

FIG. 10 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to a second aspect.

FIG. 11 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to the second aspect.

FIG. 12 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to the second aspect.

FIG. 13 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to a third aspect.

FIG. 14 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to the third aspect.

FIG. 15 is a diagram illustrating the procedure of reconnection usingS-NSSAI according to the third aspect.

FIG. 16 is a diagram illustrating the procedure of reconnection usingS-NSSAI when the AMF is changed according to the fourth aspect.

DESCRIPTION OF EMBODIMENTS

(Mobile Communication System According to the Present Disclosure)

A mobile communication system according to the present disclosure willbe described below with reference to FIGS. 1 to 6.

FIG. 1 is a diagram illustrating an exemplary device configuration of aUE. This UE 10 may be a computer device that operates as a processorexecutes a computer program stored in a memory. The UE 10 may be, forexample, a cellular phone terminal, a smartphone terminal, or a tabletterminal. Alternatively, the UE 10 may be an internet-of-things (IoT)terminal or a machine-type communication (MTC) terminal.

The UE 10 includes a communication unit 11 and a control unit 12. Thecommunication unit 11 and the control unit 12 may be each software or amodule the processing of which is executed as a processor executes acomputer program stored in a memory. Alternatively, the communicationunit 11 and the control unit 12 may be each a hardware component such asa circuit or a chip.

The communication unit 11 is a functional component for the UE 10 toconnect to an access network and connect to a core network through theaccess network. In other words, the UE 10 can transmit and receive userdata and/or control information to and from an access network and/or acore network through the communication unit 11.

The control unit 12 is a functional component for controlling the UE 10and achieves various kinds of processing of the entire UE 10 by readingand executing various kinds of information and computer programs storedin a memory.

An exemplary configuration of the UE 10 to be described in each aspectto be described later will be described below in detail with referenceto FIG. 3.

FIG. 3 is a block diagram illustrating an exemplary configuration of theUE 10. A radio frequency (RF) transceiver 1101 performs analog RF signalprocessing for non-3GPP access such as a WLAN, and communication with anevolved NodeB (eNB) or a next generation NodeB (gNB). The analog RFsignal processing performed by the RF transceiver 1101 includesfrequency up-conversion, frequency down-conversion, and amplification.The RF transceiver 1101 is connected to an antenna 1102 and a basebandprocessor 1103. Specifically, the RF transceiver 1101 receivesmodulation symbol data from the baseband processor 1103, generates atransmission RF signal, and supplies the transmission RF signal to theantenna 1102. The modulation symbol data may be orthogonal frequencydivision multiplexing (OFDM) symbol data.

In addition, the RF transceiver 1101 generates a baseband receivedsignal based on a reception RF signal received by the antenna 1102 andsupplies the baseband received signal to the baseband processor 1103.The UE 10 may perform communication by using wired media. In this case,the radio frequency (RF) transceiver 1101 is not connected to theantenna 1102 and operates as an adapter for communication with the wiredmedia.

The baseband processor 1103 performs digital baseband signal processing(data plane processing) and control plane processing for wirelesscommunication. The digital baseband signal processing includes (a) datacompression/decompression, (b) data segmentation/concatenation, and (c)transmission format (transmission frame) generation/decomposition. Thedigital baseband signal processing includes (d) transmission pathencoding/decoding. The digital baseband signal processing includes (e)modulation (symbol mapping)/demodulation and (f) OFDM symbol data(baseband OFDM signal) generation by inverse fast Fourier transform(IFFT). The control plane processing includes communication managementof Layer 1 (e.g., transmission electric power control) and Layer 2(e.g., wireless resource management, and hybrid automatic repeat request(HARQ) processing). The control plane processing includes communicationmanagement of Layer 3 (e.g., signaling related to attach, mobility, andcall management).

For example, in cases of LTE (Long Term Evolution), and LTE-Advanced,the digital baseband signal processing by the baseband processor 1103may include signal processing of a packet data convergence protocol(PDCP) layer. The digital baseband signal processing may include signalprocessing of a radio link control (RLC) layer, a medium access control(MAC) layer, and a physical (PHY) layer. The control plane processing bythe baseband processor 1103 may also include processing of a non-accessstratum (NAS) protocol, a radio resource control (RRC) protocol, and aMAC control element (CE).

The baseband processor 1103 may include a modem processor (e.g., digitalsignal processor (DSP)) that performs the digital baseband signalprocessing. The baseband processor 1103 may include a protocol stackprocessor that performs the control plane processing. The protocol stackprocessor may be, for example, a central processing unit (CPU) or amicro processing unit (MPU). In this case, the protocol stack processorthat performs the control plane processing may be common to anapplication processor 1104 to be described later.

The application processor 1104 is also called a CPU, an MPU, amicroprocessor, and a processor core. The application processor 1104 mayinclude a plurality of processors (a plurality of processor cores). Theapplication processor 1104 executes a system software program (operatingsystem (OS)) read from a memory 1106 or a non-illustrated memory. Theapplication processor implements various kinds of functions of the UE 10by executing various application programs. The application programs maybe, for example, a call application, a WEB browser, a mailer, a cameraoperation application, and a music playback application.

In some implementations, the baseband processor 1103 and the applicationprocessor 1104 may be integrated on one chip as illustrated with adashed line (1105) in FIG. 3. In other words, the baseband processor1103 and the application processor 1104 may be implemented as onesystem-on-chip (SoC) device 1105. A SoC device is also called a systemlarge-scale integration (LSI) or a chip set.

The memory 1106 is a transitory memory, a non-transitory memory, or acombination thereof. The memory 1106 may include a plurality ofphysically independent memory devices. The transitory memory is, forexample, a static random-access memory (SRAM), a dynamic RAM (DRAM), ora combination thereof. The non-transitory memory is a mask read-onlymemory (MROM), an electrically erasable programmable ROM (EEPROM), aflash memory, or a hard disk drive. Alternatively, the non-transitorymemory is an optional combination thereof. For example, the memory 1106may include an external memory device that is accessible from thebaseband processor 1103, the application processor 1104, and the SoC1105. The memory 1106 may include a built-in memory device integrated inthe baseband processor 1103, in the application processor 1104, or inthe SoC 1105. The memory 1106 may include a memory in a universalintegrated circuit card (UICC).

The memory 1106 may store a software module (computer program) includinga command group and data for performing processing by the UE 10described above in a plurality of aspects. In some implementations, thebaseband processor 1103 or the application processor 1104 may beconfigured to perform processing of the UE 10 in an aspect to bedescribed later by reading the software module from the memory 1106 andexecuting the software module.

FIG. 2 illustrates an exemplary device configuration of an access andmobility management function (AMF) 30. The AMF 30 includes acommunication unit 31 and a control unit 32. The communication unit 31and the control unit 32 may be each software or a module the processingof which is executed as a processor executes a computer program storedin a memory. Alternatively, the communication unit 31 and the controlunit 32 may be each a hardware component such as a circuit or a chip.

The communication unit 31 is a functional component for the AMF 30 toconnect to an access network or a core network device included in a corenetwork. In other words, the AMF 30 can transmit and receive user dataand/or control information to and from the access network and/or thecore network device included in the core network through thecommunication unit 31.

The control unit 32 is a functional component for controlling the AMF 30and achieves various kinds of processing of the entire AMF 30 by readingand executing various kinds of information and computer programs storedin a memory.

An exemplary configuration of the AMF 30 in a plurality of aspects to bedescribed later will be described below in detail with reference to FIG.4.

FIG. 4 is a block diagram illustrating an exemplary configuration of theAMF 30. As illustrated in FIG. 4, the AMF 30 includes a networkinterface 1201, a processor 1202, and a memory 1203. The networkinterface 1201 is used to communicate with another network node deviceincluded in the communication system. The network interface 1201 mayinclude, for example, a network interface card (NIC) compliant with IEEE802.3 series.

The processor 1202 performs processing of the AMF 30 described withreference to a sequence diagram in the above-described aspect by readingand executing software (computer program) from the memory 1203. Theprocessor 1202 may be, for example, a microprocessor, a micro processingunit (MPU), or a central processing unit (CPU). The processor 1202 mayinclude a plurality of processors.

The memory 1203 is configured as a combination of a transitory memoryand a non-transitory memory. The memory 1203 may include a storagedisposed separately from the processor 1202. In this case, the processor1202 may access the memory 1203 through a non-illustrated I/O interface.

In the example illustrated in FIG. 4, the memory 1203 is used to store asoftware module group. The processor 1202 can perform processing of theAMF 30 in an aspect to be described later by reading the software modulegroup from the memory 1203 and executing the software module group.

As described with reference to FIG. 4, each processor included in theAMF 30 executes one or a plurality of computer programs including acommand group for causing a computer to perform an algorithm describedwith reference to the accompanying drawings.

In the above-described example, a computer program can be stored byusing various types of non-transitory computer-readable media andsupplied to a computer. The non-transitory computer-readable mediainclude various types of tangible storage medium. Examples of thenon-transitory computer-readable media include a magnetic storage medium(for example, a flexible disk, a magnetic tape, or a hard disk drive),and a magneto-optical storage medium (for example, a magneto-opticaldisk). Examples of the non-transitory computer-readable media furtherinclude a CD-ROM (read-only memory), a CD-R, and a CD-R/W. In addition,examples of the non-transitory computer-readable media include asemiconductor memory. The semiconductor memory includes, for example, amask ROM, a programmable ROM (PROM), an erasable PROM (EPROM), a flashROM, and a random-access memory (RAM). A computer program may besupplied to a computer through various types of transitorycomputer-readable media. Examples of the transitory computer-readablemedia include an electric signal, an optical signal, and anelectromagnetic wave. The transitory computer-readable media can supplya computer program to a computer through a wired communication path suchas an electrical line or an optical fiber or through a wirelesscommunication path.

Key terms and information will be described below before the followingdescription of procedure examples according to aspects. Note thatinformation in each aspect may be information included in a messagetransmitted and received between the UE and the AMF, information held inthe UE, or information held in the core network.

The core network means at least some of the AMF 30, a session managementfunction (SMF) 40, a user plane function (UPF) 50, unified datamanagement (UDM) 60, and authentication, authorization, and accounting(AAA) 70 and may be referred to as a core network or a core networkdevice. Thus, message transmission-reception and/or procedure executionby the core network means message transmission-reception and/orprocedure execution by a device in the core network.

The access network is a wireless network through which the UE and thecore network are connected. The access network may be a 3GPP network ora non-3GPP network. The 3GPP network may be an NG-(R)AN 20, means atleast one of a gNB 21 and an ng-eNB 22, and may be referred to as anNG-(R)AN or an NG-(R)AN device. Thus, message transmission-receptionand/or procedure execution by the NG-(R)AN means messagetransmission-reception and/or procedure execution by a device in theNG-(R)AN. Note that the gNB may be a gNB having a new radio (NR)function and included in the NG-(R)AN. The ng-eNB 22 may be an eNBhaving an evolved universal terrestrial radio access (E-UTRA) functionand included in the NG-(R)AN.

An N1 mode is a UE mode in which the core network can be accessedthrough the access network. The N1 mode may be a UE mode in whichmessage transmission-reception is possible through an N1 interface.

An S1 mode is a UE mode in which message transmission-reception ispossible through an S1 interface. Note that the S1 interface may beconfigured by an S1-MME interface and an S1-U interface.

The core network manages the position of the UE in the unit of a set ofadjacent cells, which are each called a tracking area (TA). The trackingarea is identified by a tracking area identifier (TAI).

A tracking area list (also referred to as a TA list) is a list includingone or more TAs. A set of one or more TAs is also expressed as aregistration area (RA).

First network slice information may be requested NSSAI and may be NSSAItransferred by the UE in a registration procedure. The UE may includethe first network slice information in an initial registration, mobilityregistration update, or periodic registration update message.

First support information may be information indicating whether the UEsupports the procedure of network slice-specific authentication andauthorization (NSSAA) or may be capability information. The UE mayinclude the first support information in an initial registration,mobility registration update, or periodic registration update message.

The procedure of network slice-specific authentication and authorizationmay be the procedure of authentication and authorization requested foreach network slice.

Second network slice information may be allowed NSSAI or may be NSSAIavailable at a place (current registration area) where the UE islocated. The NSSAI available at a place (current registration area)where the UE is located may be notified by the core network. The corenetwork may include the second network slice information in aregistration accept message, in a configuration update command (UEsetting information update command control signal or control message),or in a downlink (DL) NAS transport message.

Third network slice information may be rejected NSSAI or may be one ormore pieces of S-NSSAI rejected by the core network. The core networkmay include the third network slice information in a registration acceptmessage, in a registration reject message, in a de-registration requestmessage, in a configuration update command (UE setting informationupdate command control signal or control message), or in a DL NAStransport message. The rejected NSSAI may be a list in which one or morepieces of S-NSSAI rejected by the core network are each associated witha reason value of rejection of the S NSSAI. The third network sliceinformation may be NSSAI including S-NSSAI having a predetermined causevalue (reason value or rejection reason value). The predetermined causevalue may be at least one of first to fourth reason values to bedescribed later.

A first reason value may be a cause value (reason value or rejectionreason value) associated with each S-NSSAI included in the third networkslice information. Note that the first reason value may be a reasonvalue indicating pending. Alternatively, the first reason value may be areason value indicating that the procedure of network slice-specificauthentication and authorization is being executed, an execution target,or scheduled to be executed. In each aspect, the first reason value isalso expressed as a “reason value indicating pending” for sake ofdescription. In some instances in which a plurality of pieces of S-NSSAIare set to the third network slice information, the first reason valuemay be associated with each S-NSSAI or with the third network sliceinformation (rejected NSSAI) as an assembly of the pieces of S-NSSAI.For S-NSSAI associated with the reason value, the UE may preventtransmission of a registration request (initial registration request,mobility registration update, or periodic registration update) using theS-NSSAI until the procedure of network slice-specific authentication andauthorization is successfully executed, terminal power on/off, orinsertion and removal of a universal subscriber identity module (USIM).Note that the case in which the procedure of network slice-specificauthentication and authorization is successfully executed may be a casein which the UE has received extensible authentication protocol (EAP)success from the core network. The core network may include the firstreason value in a registration accept message, in a registration rejectmessage, in a de-registration request message, in a configuration updatecommand (UE setting information update command control signal or controlmessage), or in a DL NAS transport message.

A second reason value may be a cause value (reason value or rejectionreason value) associated with each S-NSSAI included in the third networkslice information. Note that the second reason value may be a reasonvalue indicating success or failure. Alternatively, the second reasonvalue may be a reason value indicating that the procedure of networkslice-specific authentication and authorization has been successful as aresult of execution, and is also expressed as a “reason value indicatingsuccess” for sake of description in each aspect. Alternatively, thesecond reason value may be a reason value indicating that the procedureof network slice-specific authentication and authorization has failed asa result of execution, and is also expressed as a “reason valueindicating failure” for sake of description in each aspect. In someinstances in which a plurality of pieces of S-NSSAI are set to the thirdnetwork slice information, the second reason value may be associatedwith each S-NSSAI or with the third network slice information (rejectedNSSAI) as an assembly of the pieces of S-NSSAI. The UE 10 may hold theassociation of the reason value and the third network slice informationuntil terminal power on/off or insertion and removal of a universalsubscriber identity module (USIM). When the second reason value is thereason value indicating failure, the UE 10 may prevent transmission of aregistration request (initial registration request, mobilityregistration update, or periodic registration update) using the S-NSSAIuntil terminal power on/off or insertion and removal of a universalsubscriber identity module (USIM). The core network may include thesecond reason value in a registration accept message, in a registrationreject message, in a de-registration request message, in a configurationupdate command (UE setting information update command control signal orcontrol message), or in a DL NAS transport message.

A third reason value may be a cause value (reason value or rejectionreason value) associated with each S-NSSAI included in the third networkslice information. Note that the third reason value may be a reasonvalue indicating “S-NSSAI not available in the current PLMN” written inSection 9.11.3.46 of Non Patent Literature 3. The reason valueindicating “S-NSSAI not available in the current PLMN” may be a reasonvalue indicating that the S-NSSAI is not available in a public landmobile network (PLMN) accessed by the UE. In other words, when havingmoved to another PLMN, the UE 10 may be able to perform reconnection(registration request) by using the S-NSSAI. In some instances in whicha plurality of pieces of S-NSSAI are set to the third network sliceinformation, the third reason value may be associated with each S-NSSAIor with rejected NSSAI as an assembly of the pieces of S-NSSAI. Notethat the UE 10 may hold the association of the reason value and thethird network slice information until terminal power on/off or insertionand removal of a universal subscriber identity module (USIM). The corenetwork may include the third reason value in a registration acceptmessage, in a registration reject message, in a de-registration requestmessage, in a configuration update command (UE setting informationupdate command control signal or control message), or in a DL NAStransport message.

A fourth reason value may be a cause value (reason value or rejectionreason value) associated with each S-NSSAI included in the third networkslice information. Note that the fourth reason value may be a reasonvalue indicating “S-NSSAI not available in the current registrationarea” written in Section 9.11.3.46 of Non Patent Literature 3. Thereason value indicating “S-NSSAI not available in the currentregistration area” may be a reason value indicating that the S-NSSAI isnot available in a registration area where the UE is located. In otherwords, when having moved to another RA, the UE 10 may be able to performreconnection (registration request) by using the S-NSSAI. In someinstances in which a plurality of pieces of S-NSSAI are set to the thirdnetwork slice information, the fourth reason value may be associatedwith each S-NSSAI or with the third network slice information (rejectedNSSAI) as an assembly of the pieces of S-NSSAI. Note that the UE 10 mayhold the association of the reason value and the third network sliceinformation until terminal power on/off or insertion and removal of auniversal subscriber identity module (USIM). The core network mayinclude the fourth reason value in a registration accept message, in aregistration reject message, in a de-registration request message, in aconfiguration update command (UE setting information update commandcontrol signal or control message), or in a DL NAS transport message.

First timer information may be a timer value set to a timer 1. The timer1 may be a timer with which the UE manages (transmits or preventstransmission of) a registration request message (the registrationrequest message is an initial registration request, mobilityregistration update, or periodic registration update) using S-NSSAIincluded in the third network slice information and S-NSSAI associatedwith the first reason value. In other words, the timer 1 may be a timerconfigured to manage (transmit or prevent transmission of) reconnection(registration request transmission/retransmission) using pendingS-NSSAI. In some instances, the timer 1 may be a timer for waitingreception of an EAP identity request (control signal or control messagewith which the core network requests an EAP identifier to the UE), maybe a timer for waiting reception of EAP success or EAP failure (controlsignal or control message that means EAP authentication completion), ormay be a timer for waiting reception of a configuration update command(UE setting information update command control signal or controlmessage) that triggers acquisition of new slice information.Alternatively, the timer 1 may be a timer for determining whether thenetwork is abnormal during the procedure of network slice-specificauthentication and authorization. The core network may include the firsttimer information in a registration accept message or in a registrationreject message.

Fourth network slice information may be configured NSSAI. The corenetwork may include the fourth network slice information in aregistration accept message, in a configuration update command (UEsetting information update command control signal or control message),or in a DL NAS transport message.

The second network slice information may be information indicating thatno S-NSSAI is available at a place (current registration area) where theUE is located, or may be empty allowed NSSAI. The second network sliceinformation in this case is also referred to as fifth network sliceinformation in the following description. The core network may includethe fifth network slice information in a registration accept message orin a registration reject message.

First instruction information (indication) may be instructioninformation that the core network transmits to prompt or request the UEto execute a registration procedure. Note that the core network mayinclude the first instruction information in a configuration updatecommand (UE setting information update command control signal or controlmessage), in a de-registration request message, or in a registrationreject message.

An example of initial procedure (hereinafter also referred to as thepresent procedure) as the premise of each aspect will be described belowwith reference to FIG. 5. The example of the present procedure includesa registration procedure.

The example of the present procedure included in FIG. 5 will bedescribed in detail as follows.

Step (1): the UE 10 transmits the first network slice information(requested NSSAI) and the first support information to the accessnetwork (for example, the NG-(R)AN 20) on the N1 interface (S0501).Specifically, the UE 10 transmits a radio resource control (RRC) messageincluding a registration request message to the access network. Theregistration request message may be an initial registration request, amobility registration update, or a periodic registration update.

Step (2): the access network selects, based on the registration requestmessage included in the RRC message, the AMF 30 at the transmissiondestination of the registration request message (S0502). Thus, theaccess network may select the AMF 30 based on information included inthe RRC message.

Step (3): the access network transmits or transparently forwards theregistration request message to the selected AMF 30 (S0503). In thiscase, the registration request may include the first network sliceinformation (requested NSSAI) and the first support information. Notethat a message related to the registration procedure and transmitted andreceived on the N1 interface between the UE 10 and the AMF 30 is amessage processed at a non-access-stratum (NAS) layer. The NAS layer isa higher-level layer of an RRC layer between the UE 10 and the NG-(R)AN20.

Step (4): the AMF 30 receives the registration request message andexecutes a registration procedure written in Section 4.2.2 of Non PatentLiterature 2 (S0504).

As written in Section 5.15 of Non Patent Literature 1, the AMF 30 setsone or more pieces of S-NSSAI as the second network slice information(allowed NSSAI) based on, for example, subscriber information and/or anaccess type (S0504).

In some instances when the first support information is included in theregistration request message received at Step (1), the AMF 30 setsS-NSSAI as a target of network slice-specific authentication andauthorization to the third network slice information (rejected NSSAI).Note that the S-NSSAI set to the third network slice information doesnot necessarily need to be S-NSSAI as a target of network slice-specificauthentication and authorization in a home PLMN (HPLMN). The S-NSSAI setto the third network slice information may be S-NSSAI provided by aserving PLMN and to which S-NSSAI as a target of network slice-specificauthentication and authorization in a HPLMN is mapped. The AMF 30determines or specifies S-NSSAI as a target of network slice-specificauthentication and authorization based on the subscriber information.Specifically, during the registration procedure written in Section 4.2.2of Non Patent Literature 1 described above, S-NSSAI as a target ofnetwork slice-specific authentication and authorization is determined orspecified based on the subscriber information (S504) that the AMF 30receives from the UDM 60.

Step (5): for example, when the AMF 30 is updated, the AMF 30 updates,for the SMF 40, information of a protocol data unit (PDU) session(S0505).

In some instances when the first network slice information (requestedNSSAI) is not included in the RRC message including the registrationrequest message received at Step (1) or when S-NSSAI as a target ofnetwork slice-specific authentication and authorization is not includedin the first network slice information (requested NSSAI), the AMF 30 mayspecify S-NSSAI as a target of network slice-specific authentication andauthorization based on the subscriber information. Specifically, in thiscase, the AMF 30 determines whether one or more pieces of defaultS-NSSAI set to the subscriber information (S0504) acquired from the UDM60 are targets of network slice-specific authentication andauthorization. When the pieces of default S-NSSAI are targets of networkslice-specific authentication and authorization, the AMF 30 determinesthe pieces of S-NSSAI as a target of network slice-specificauthentication and authorization.

In some instances when all pieces of S-NSSAI included in the firstnetwork slice information (requested NSSAI) received at Step (1) aretargets of network slice-specific authentication and authorization, theAMF 30 may set the fifth network slice information as empty allowedNSSAI. In other words, nothing may be set to allowed NSSAI as the fifthnetwork slice information.

In some instances when the first network slice information (requestedNSSAI) is not included in the RRC message including the registrationrequest message received at Step (1) and all pieces of default S-NSSAIset to the subscriber information are targets of network slice-specificauthentication and authorization, the AMF 30 may set the fifth networkslice information as empty allowed NSSAI. In other words, nothing may beset to allowed NSSAI as the fifth network slice information.

In some instances when all pieces of S-NSSAI included in the firstnetwork slice information (requested NSSAI) received at Step (1) do notmatch a set (subscribed NSSAI) of pieces of S-NSSAI recorded in thesubscriber information and all pieces of default S-NSSAI set to thesubscriber information are targets of network slice-specificauthentication and authorization, the AMF 30 may set empty allowed NSSAIas the fifth network slice information. In other words, nothing may beset to allowed NSSAI as the fifth network slice information.

Step (6): the AMF 30 sets one or more pieces of S-NSSAI as a target ofnetwork slice-specific authentication and authorization to the thirdnetwork slice information (rejected NSSAI), and transmits the thirdnetwork slice information and the second network slice information, or aregistration accept message including any of the third network sliceinformation and the fifth network slice information to the UE 10 on theN1 interface (S0506).

Note that one or more pieces of S-NSSAI included in the third networkslice information (rejected NSSAI) do not necessarily need to be S-NSSAIas a target of network slice-specific authentication and authorizationin a HPLMN. One or more pieces of S-NSSAI included in the third networkslice information (rejected NSSAI) may be S-NSSAI provided by a servingPLMN to which S-NSSAI as a target of network slice-specificauthentication and authorization in a HPLMN is mapped.

Step (7): the UE 10 recognizes and holds contents of various kinds ofinformation acquired from the registration accept message. For example,the UE 10 may recognize and hold the second network slice information orthe fifth network slice information as allowed NSSAI. The UE 10 mayrecognize and hold the third network slice information as rejectedNSSAI.

Then, upon reception of the registration accept message, the UE 10transmits a registration completion message on the N1 interface (S0507).

Accordingly, the initial procedure ends, and the procedure of networkslice-specific authentication and authorization illustrated in FIG. 6 isperformed (first state). The first state is a state in which the initialprocedure illustrated in FIG. 5 has ended, and is a state in which theprocedure of network slice-specific authentication and authorization iswaited.

An example of the procedure of network slice-specific authentication andauthorization (hereinafter also referred to as the present procedure)according to each aspect will be described below with reference to FIG.6. The example of the present procedure includes the procedure ofnetwork slice-specific authentication and authorization.

Step (1): as written in Section 4.2.2.2 and Section 4.2.9.2 of NonPatent Literature 2, the AMF 30 may trigger start of the procedure ofnetwork slice-specific authentication and authorization after theregistration procedure completion (after registration accepttransmission, after registration complete message reception, or after5GS mobility management (SGMM) context establishment) (S0601).

In this case, the AMF 30 may hold S-NSSAI determined as a target ofnetwork slice-specific authentication and authorization, which isdescribed above at Step (4) of the registration procedure, and theprocessing state of the procedure of network slice-specificauthentication and authorization in association with each other. Inother words, the AMF 30 may hold, as UE context information, stateinformation indicating S-NSSAI for which the procedure of networkslice-specific authentication and authorization is being executed, anexecution target, or scheduled to be executed. The state information maybe information indicating that the procedure of network slice-specificauthentication and authorization is pending or is success or failure forthe S-NSSAI.

The AMF 30 may determine, based on the state information, a trigger ofstart of the procedure of network slice-specific authentication andauthorization, or S-NSSAI for which the procedure of networkslice-specific authentication and authorization is to be executed. Forexample, when the state information indicating that the procedure ofnetwork slice-specific authentication and authorization for particularS-NSSAI is success is included in the UE context information, the AMF 30does not need to execute or may skip the procedure of networkslice-specific authentication and authorization for the S-NSSAI.

Steps (2, 3): the AMF 30 executes the EAP-utilized procedure of networkslice-specific authentication and authorization written in Section4.2.9.2 of Non Patent Literature 2 (S0602 and S0603).

Step (4): after notifying (S0604) the UE of an execution result (EAPsuccess or EAP failure) of the procedure of network slice-specificauthentication and authorization, the AMF 30 may transmit aconfiguration update command toward the UE as written in Section 4.2.9.2of Non Patent Literature 2. Specifically, when the second network sliceinformation or the fifth network slice information (allowed NSSAI) thatare new is set to the UE, when the third network slice information(rejected NSSAI) that is new is set to the UE, or when a serving AMF ischanged to another different AMF, the AMF 30 may transmit aconfiguration update command toward the UE for each access type. Notethat the access type indicates the type of the access network and maymean a 3GPP network or a non 3GPP network.

The example of the initial procedure and the example of the procedure ofnetwork slice-specific authentication and authorization as the premiseof each aspect is described so far. In each aspect of the presentdisclosure, various problem scenarios that a service using a networkslice-specific authentication and authorization function cannot beprovided are considered on the above-described premise, and optimumsolution of each problem scenario will be described in an individualaspect.

(First Aspect)

FIG. 7 is a diagram for description of a first aspect.

The present aspect relates to a scenario that, after execution of stepsS0501 to S0505 in FIG. 5, the UE 10 receives the third network sliceinformation including S-NSSAI associated with the first reason value andwaits the procedure of network slice-specific authentication andauthorization in place of the processing at step S0506. The UE 10supports the procedure of network slice-specific authentication andauthorization. The wait of the procedure of network slice-specificauthentication and authorization is a state in which the UE 10 holds oneor more pieces of S-NSSAI associated with the reason value indicatingpending as the first reason value after registration accept reception,after registration completion message transmission, or after SGMMcontext establishment. Specifically, the wait of the procedure ofnetwork slice-specific authentication and authorization may mean a casein which no EAP identity request is received, neither EAP success norEAP failure is received, no message (configuration update command orde-registration request) that triggers acquisition of new sliceinformation is received, or no message (DL NAS transport) for settingnew slice information is received.

In a solution described below, the UE 10 manages, based on a timer 1and/or a first timer value acquired from the core network or based on atimer 1 and/or a first timer value set to the UE 10 in advance,transmission of a registration request (initial registration request,mobility registration update, or periodic registration update) usingS-NSSAI that has been associated with the first reason value (reasonvalue indicating pending). Note that the management of transmission maymean management of the behavior of transmission and the behavior oftransmission prevention, and the behavior of transmission is alsoexpressed as re-attempt (reconnection).

A step illustrated in FIG. 7 will be described in detail as follows.

Step (1): after having executed the processing at steps S0501 to S0505in FIG. 5, the UE 10 receives the first timer information from the AMF30 in addition to at least one of the third network slice informationand the first reason value (S0701). The reception of the first timerinformation may be performed upon transmission of a registrationcomplete message toward the AMF 30 by the UE 10. When the timer 1 and/orthe first timer value is set to the UE 10 in advance, the first timerinformation does not necessarily need to be received.

In this case, the UE 10 may hold one or more pieces of S-NSSAI indicatedby the third network slice information in association with the firstreason value (reason value indicating pending). In addition, afterhaving transmitted a registration accept message to the UE 10 or havingreceived a registration complete message from the UE 10, the AMF 30 mayhold one or more pieces of S-NSSAI indicated by the third network sliceinformation in association with the first reason value (reason valueindicating pending) as UE context information. The AMF 30 may hold oneor more pieces of S-NSSAI indicated by the third network sliceinformation and/or may hold the first timer information as UE contextinformation in association with the first reason value (reason valueindicating pending).

Step (2): the UE 10 performs first processing example (S0702). In thefirst processing example, the UE 10 may perform one or more of first tothird behavior examples. The first processing example includesprocessing including behavior (first behavior example) that the UE 10activates the timer 1 for determining whether the network is abnormalduring the procedure of network slice-specific authentication andauthorization, behavior (second behavior example) until the timer 1expires or stops, and behavior (third behavior example) when the timer 1has expired or stopped.

The first behavior example in the present aspect may be behavior thatthe UE 10 sets, to the timer 1, a timer value indicated by the firsttimer information or a value set to the UE 10 in advance and activatesthe timer 1. Note that the activation of the timer 1 may mean start ofcounting at the timer. The timer value set to the UE 10 in advance maybe set to the UE 10 so that the timer value is used when the UE 10 islocated in a HPLMN or an equivalent PLMN.

The UE 10 may activate the timer 1 in the unit of one or more pieces ofS-NSSAI associated with the first reason value (reason value indicatingpending) in the third network slice information (rejected NSSAI), or inthe unit of at least one or a combination of S-NSSAI, subscriberidentity module (SIM), UE, and PLMN. In other words, the first timerinformation including the timer value of the timer 1 may be set in theunit of one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) in the third network sliceinformation (rejected NSSAI), or in the unit of at least one or acombination of S-NSSAI, SIM, UE, and PLMN. For example, the UE 10 mayactivate the timer 1 in the unit of one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI), may activatethe timer 1 in the unit of SIM, may activate the timer 1 in the unit ofUE, may activate the timer 1 in the unit of PLMN. For example, the UE 10may activate the timer 1 in a combination of the unit of one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI) and the unit of PLMN, may activate the timer 1 in a combinationof the unit of one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) and the unit of SIM, ormay activate the timer 1 in a combination of the unit of one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) and the unit of UE. For example, the UE 10 mayactivate the timer 1 in a combination of the unit of SIM and the unit ofPLMN or may activate the timer 1 in a combination of the unit of UE andthe unit of PLMN. For example, the UE 10 may activate the timer 1 in acombination of the unit of one or more pieces of S-NSSAI associated withthe first reason value (reason value indicating pending) in the thirdnetwork slice information (rejected NSSAI), the unit of UE, and the unitof PLMN, may activate the timer 1 in a combination of the unit of one ormore pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI), the unit of SIM, and the unit of PLMN, and mayactivate the timer 1 in a combination of the unit of SIM, the unit ofUE, and the unit of PLMN. For example, the UE 10 may activate the timer1 in a combination of the unit of one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI), the unit ofSIM, the unit of UE, and the unit of PLMN.

Note that, in a case in which there are two or more pieces of S-NSSAIassociated with the first reason value (reason value indicatingpending), the first timer information may be obtained as the product ofthe timer value of a single piece of S-NSSAI and the number of pieces ofS-NSSAI associated with the first reason value (reason value indicatingpending).

In the first behavior example in the present aspect, the UE 10 mayperform N repetitions of an operation to reactivate the timer 1 eachtime the timer 1 expires. The value N as the number of repetitions ofthe operation may be a value determined based on configuration data heldby the UE 10. Alternatively, the value N indicating N times may be setto a registration accept message, a registration reject message, aconfiguration update command (UE setting information update commandcontrol signal or control message), or a DL NAS transport message thatare transmitted from the AMF 30, and the AMF 30 may transmit the messageto the UE 10, so that the value N is set to the UE 10. In this case, thesecond behavior example to be described below may be activated until thetimer 1 is activated or expires N times, and the third behavior exampleto be described later may be activated after N times of activation andexpiration of the timer 1.

The second behavior example in the present aspect may include behaviorthat, until the timer 1 being activated stops or expires, the UE 10prevents transmission of a registration request (initial registrationrequest, mobility registration update, or periodic registration update)using one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) in the third network sliceinformation (rejected NSSAI), or S-NSSAI of a serving PLMN to which oneor more pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI) are mapped.

The second behavior example in the present aspect may be behavior that,until the timer 1 being activated stops or expires, the UE 10 transmits,irrespective of the third network slice information (rejected NSSAI), anemergency registration request using one or more pieces of S-NSSAIassociated with the reason value indicating pending in the third networkslice information (rejected NSSAI), S-NSSAI of a serving PLMN to whichone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) are mapped.

In the second behavior example in the present aspect, when the procedureof network slice-specific authentication and authorization is completedfor one or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI), or S-NSSAI of a serving PLMN to which one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI) are mapped, the UE 10 may delete the S-NSSAI from the thirdnetwork slice information (rejected NSSAI). The UE 10 may manage, as thesecond network slice information (allowed NSSAI), the S-NSSAI deletedfrom the third network slice information. In addition, the UE 10 maystart a service using the S-NSSAI managed as the second network sliceinformation (allowed NSSAI).

The third behavior example in the present aspect may include behaviorthat, when the timer 1 being activated has stopped or expired, the UE 10updates at least one of: one or more pieces of S-NSSAI corresponding tothe first reason value (reason value indicating pending) and/or thethird network slice information (rejected NSSAI).

Specifically, the UE 10 may perform a first procedure example below asthe third behavior example.

In the present aspect, when the timer 1 being activated has stopped orexpired, the UE 10 may cancel the association of the first reason value(reason value indicating pending) and one or more pieces of S-NSSAIcorresponding to the third network slice information (rejected NSSAI),which are held by the UE 10. The cancellation of the association of thefirst reason value (reason value indicating pending) and one or morepieces of S-NSSAI corresponding to the third network slice information(rejected NSSAI) may mean deletion of the first reason value (reasonvalue indicating pending) for one or more pieces of S-NSSAIcorresponding to the third network slice information (rejected NSSAI)and the first reason value (reason value indicating pending), which areheld by the UE 10, or may mean rewriting to the second reason value(reason value indicating failure). In this case, the UE 10 may performrewriting to the second reason value (reason value indicating failure)without message transmission and reception to and from the core networkand/or the access network (locally). Note that the deletion of the firstreason value (reason value indicating pending) may mean that no reasonvalue is associated with the one or more pieces of S-NSSAI.

In some instances, the UE 10 may perform, as the third behavior example,a second procedure example below, which is different from the firstprocedure example.

In the present aspect, when the timer 1 being activated has stopped orexpired, the UE 10 may delete one or more pieces of S-NSSAI associatedwith the first reason value (reason value indicating pending) in thethird network slice information (rejected NSSAI) held by the UE 10. Thedeletion of one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) in the third networkslice information (rejected NSSAI) may mean deletion of both of: thefirst reason value (reason value indicating pending) in the thirdnetwork slice information (rejected NSSAI) held by the UE; and one ormore pieces of S-NSSAI associated with the reason value.

In some instances, the UE 10 may perform, as the third behavior example,a third procedure example below, which is different from the first andsecond procedure examples.

In a case in which the UE 10 holds only one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) when the timer 1being activated has stopped or expired, the UE 10 may reset the thirdnetwork slice information (rejected NSSAI) held by the UE 10. Theresetting of the third network slice information (rejected NSSAI) maymean deletion of all pieces of third network slice information (rejectedNSSAI) held by the UE.

FIG. 8 is a diagram illustrating the procedure of reconnection usingS-NSSAI that has been associated with the first reason value (reasonvalue indicating pending), which is performed after the first processingexample in the present aspect.

In some instances, the UE 10 may perform a first procedure examplebelow.

Specifically, after performing the first processing example, the UE 10may transmit a registration request (initial registration request,mobility registration update, or periodic registration update) messageto the AMF 30 by using one or more pieces of S-NSSAI that have beenassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI), or S-NSSAIprovided by a serving PLMN to which one or more pieces of S-NSSAI thatare associated with the first reason value (reason value indicatingpending) in the third network slice information (rejected NSSAI) aremapped (S0801).

In some instances, the UE 10 may perform a second procedure examplebelow.

Specifically, when the timer 1 being activated has stopped or expired asillustrated in FIG. 8, the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message withoutusing one or more pieces of S-NSSAI associated with the third networkslice information (rejected NSSAI) that has been associated with thefirst reason value (reason value indicating pending) (S0801).Specifically, in the second procedure example, one or more pieces ofS-NSSAI that have been associated with the reason value indicatingpending in the third network slice information (rejected NSSAI) are notset to the first network slice information (requested NSSAI) set to theregistration request (initial registration request, mobilityregistration update, or periodic registration update) message.Alternatively, the UE 10 may set, as an individual information elementto the registration request (initial registration request, mobilityregistration update, or periodic registration update) message, one ormore pieces of S-NSSAI already associated with the third network sliceinformation (rejected NSSAI) and pending and may transmit the individualinformation element to the AMF 30. The AMF 30 may activate, for theS-NSSAI received as the individual information element, operation andmaintenance (O&M) such as check of whether the procedure of networkslice-specific authentication and authorization is normal. Note that oneor more pieces of S-NSSAI that have been associated with the firstreason value (reason value indicating pending) in the third networkslice information (rejected NSSAI) may be one or more pieces of S-NSSAIthe associated reason value of which is deleted or replaced with thesecond reason value (reason value indicating failure) as described inthe first procedure example of the third behavior example of the firstprocessing example.

The AMF 30 receives a registration request message without using one ormore pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI). Subsequently, the AMF 30 may set the second networkslice information to a registration accept message when the secondnetwork slice information that is new (allowed NSSAI) is to be set tothe UE, may set the third network slice information and the secondreason value (reason value indicating failure) to a registration acceptmessage when the third network slice information (rejected NSSAI) thatis new is to be set to the UE, may set the fourth network sliceinformation to a registration accept message when the fourth networkslice information that is new (configured NSSAI) is to be set to the UEand may transmit a registration accept message including the informationto the UE 10 (S0802).

Note that, even when the UE 10 has deleted, or rewritten to the secondreason value (reason value indicating failure), a reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) based on the first procedureexample of the third behavior example of the first processing example,the AMF 30 may recognize, as the first reason value (reason valueindicating pending), the reason value associated as UE contextinformation with the S-NSSAI. In other words, the reason valuerecognized by the AMF 30 may be different from the reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) recognized by the UE 10. Thereason value recognized by the AMF 30 is associated with one or morepieces of S-NSSAI associated with the third network slice information(rejected NSSAI).

A case in which the second network slice information is included in aregistration accept message will be described below. When one or morepieces of S-NSSAI included in the second network slice information matchone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) held by the UE 10, the UE 10 may delete the matchingone or more pieces of S-NSSAI from the third network slice information(rejected NSSAI). The UE 10 may transmit, to the AMF 30, a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) message using the one or more pieces ofS-NSSAI deleted from the third network slice information (rejectedNSSAI) (S0803).

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIcorresponding to the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as the second network sliceinformation, the UE 10 deletes S-NSSAI #1 held as S-NSSAI correspondingto the third network slice information (rejected NSSAI). In addition,the UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using S-NSSAI #1 (S0803).

A case in which the third network slice information and the secondreason value are included in a registration accept message will bedescribed below. When one or more pieces of S-NSSAI included in thethird network slice information match one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) held by the UE10, the UE 10 may rewrite a reason value associated with the matchingone or more pieces of S-NSSAI to a reason value indicated by the secondreason value. The reason value indicated by the second reason value maybe the reason value indicating failure.

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIcorresponding to the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as S-NSSAI corresponding to thethird network slice information and the second reason value (reasonvalue indicating failure), the UE 10 may rewrite, to the second reasonvalue (reason value indicating failure), the reason value associatedwith S-NSSAI #1 held as S-NSSAI corresponding to the third network sliceinformation (rejected NSSAI).

In some instances, for example, when configured NSSAI is included in thefourth network slice information, the UE 10 may delete the held thirdnetwork slice information (rejected NSSAI). In other words, when havingreceived the fourth network slice information (configured NSSAI), the UE10 may reset the held third network slice information (rejected NSSAI).In some instances, the UE 10 may transmit, to the AMF 30, a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) message using one or more pieces ofS-NSSAI associated with the fourth network slice information (configuredNSSAI) (S0803). The fourth network slice information set by the UE 10may include one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) for networkslice-specific authentication and authorization in the third networkslice information (rejected NSSAI). In other words, at step at S0803,the UE 10 can transmit a registration request (initial registrationrequest, mobility registration update, or periodic registration update)message to the AMF 30 by using one or more pieces of S-NSSAI that havebeen associated with the first reason value (reason value indicatingpending) for network slice-specific authentication and authorization,which are included in the reset third network slice information(rejected NSSAI).

For example, it is assumed that the UE 10 holds S-NSSAI #1 and S-NSSAI#2 as S-NSSAI corresponding to the third network slice information(rejected NSSAI). S-NSSAI #1 is associated with the first reason value(reason value indicating pending). S-NSSAI #2 is associated with thefourth reason value (reason value indicating “S-NSSAI not available inthe current registration area”) disclosed in Non Patent Literature 3. Inthis case, when having received a registration accept message includingthe fourth network slice information (configured NSSAI), the UE 10 maydelete both S-NSSAI #1 and S-NSSAI #2 held as S-NSSAI corresponding tothe third network slice information (rejected NSSAI) or may delete thethird network slice information (rejected NSSAI) held by the UE 10. Forexample, when S-NSSAI #1 is included in the fourth network sliceinformation (configured NSSAI), the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message usingS-NSSAI #1 included in the fourth network slice information (configuredNSSAI).

In some instances, the UE 10 may perform the third procedure examplebelow.

Specifically, when the timer 1 being activated has stopped or expired asillustrated in FIG. 9, the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message usingS-NSSAI that have been associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI) (S0901). Note that one or more pieces of S-NSSAI thathave been associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI) may be one or more pieces of S-NSSAI the associated reason valueof which is deleted or rewritten to the second reason value (reasonvalue indicating failure) as described in the first procedure of thethird behavior example of the first processing example.

The AMF 30 receives a registration request message using one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI). Subsequently, the AMF 30 may set the second network sliceinformation to a registration accept message when the second networkslice information that is new (allowed NSSAI) is set to the UE, may setthe third network slice information and the second reason value to aregistration accept message when the third network slice information(rejected NSSAI) that is new is set to the UE, may set the fourthnetwork slice information to a registration accept message when thefourth network slice information that is new (configured NSSAI) is setto the UE and may transmit a registration accept message including theinformation to the UE 10 (S0902).

Note that, even when the UE 10 has deleted, or rewritten to the secondreason value (reason value indicating failure), a reason valueassociated with one or more pieces of S-NSSAI corresponding to the thirdnetwork slice information (rejected NSSAI) based on the first procedureexample of the third behavior example of the first processing example,the AMF 30 may recognize, as the first reason value (reason valueindicating pending), the reason value associated as UE contextinformation with the S-NSSAI. In other words, the reason valueassociated with one or more pieces of S-NSSAI of the third network sliceinformation (rejected NSSAI) and recognized by the AMF 30 may bedifferent from the reason value associated with one or more pieces ofS-NSSAI corresponding to the third network slice information (rejectedNSSAI) and recognized by the UE 10.

A case in which the second network slice information is included in aregistration accept message will be described below. When one or morepieces of S-NSSAI included in the second network slice information matchone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) held by the UE 10, the UE 10 may delete the matchingone or more pieces of S-NSSAI from the third network slice information(rejected NSSAI). The UE 10 may transmit, to the AMF 30, a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) message using the one or more pieces ofS-NSSAI deleted from the third network slice information (rejectedNSSAI) (S0903).

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIcorresponding to the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as the second network sliceinformation, the UE 10 deletes S-NSSAI #1 held as S-NSSAI correspondingto the third network slice information (rejected NSSAI). In addition,the UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using S-NSSAI #1 (S0903).

A case in which the third network slice information and the secondreason value are included in a registration accept message will bedescribed below. When one or more pieces of S-NSSAI included in thethird network slice information match one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) held by the UE10, the UE 10 may rewrite a reason value associated with the matchingone or more pieces of S-NSSAI to a reason value indicated by the secondreason value. The reason value indicated by the second reason value maybe the reason value indicating failure.

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIcorresponding to the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as S-NSSAI corresponding to thethird network slice information and the second reason value (reasonvalue indicating failure), the UE 10 may rewrite, to the second reasonvalue (reason value indicating failure), the reason value associatedwith S-NSSAI #1 held as S-NSSAI corresponding to the third network sliceinformation (rejected NSSAI).

In some instances, for example, when configured NSSAI is included in thefourth network slice information, the UE 10 may delete the held thirdnetwork slice information (rejected NSSAI). In other words, when havingreceived the fourth network slice information (configured NSSAI), the UE10 may reset the held third network slice information (rejected NSSAI).The UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using one or more pieces of S-NSSAIassociated with the fourth network slice information (configured NSSAI)(S0903). The fourth network slice information set by the UE 10 mayinclude one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) for network slice-specificauthentication and authorization in the third network slice information(rejected NSSAI). In other words, at step at S0903, the UE 10 cantransmit a registration request (initial registration request, mobilityregistration update, or periodic registration update) message to the AMF30 by using one or more pieces of S-NSSAI that have been associated withthe first reason value (reason value indicating pending) for networkslice-specific authentication and authorization, which have beenincluded in the reset third network slice information (rejected NSSAI).

For example, it is assumed that the UE 10 holds S-NSSAI #1 and S-NSSAI#2 as S-NSSAI corresponding to the third network slice information(rejected NSSAI). S-NSSAI #1 is associated with the first reason value(reason value indicating pending). S-NSSAI #2 is associated with thethird reason value (reason value indicating “S-NSSAI not available inthe current registration area”) disclosed in Non Patent Literature 3. Inthis case, when having received a registration accept message includingthe fourth network slice information (configured NSSAI), the UE 10 maydelete both S-NSSAI #1 and S-NSSAI #2 held as S-NSSAI corresponding tothe third network slice information (rejected NSSAI) or may delete thethird network slice information (rejected NSSAI) held by the UE 10. Forexample, when S-NSSAI #1 is included in the fourth network sliceinformation (configured NSSAI), the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message usingS-NSSAI #1 included in the fourth network slice information (configuredNSSAI).

Note that, in the second and third procedure examples performed afterthe first processing example, it is described that, when the timer 1 hasstopped or expired, the UE 10 transmits a registration request to theAMF 30 and acquires, through registration accept as a reply to theregistration request, new network slice information (the second networkslice information, the third network slice information and the secondreason value, the fourth network slice information. In this manner, themeans for solving such a problem that the UE 10 indefinitely waits theprocedure of network slice-specific authentication and authorization isdescribed above, but the present invention is not limited thereto.

Specifically, the UE 10 may receive, from the AMF 30, a configurationupdate command including the first instruction information. The UE 10may transmit a registration request message to the AMF 30 based on thefirst instruction information, and the AMF 30 may include the secondnetwork slice information the third network slice information and thesecond reason value, and/or the fourth network slice information in aregistration accept message in response to the registration requestmessage, thereby setting new network slice information to the UE. Thebehavior of the UE 10 related to registration request transmission andregistration accept may be same as the above-described behavior of theUE 10 in the second and third procedure examples performed after thefirst processing example.

The first to third behavior examples of the first processing example maybe behavior executed based on a rule and/or a policy inside the UE 10.The UE 10 may hold a policy (UE policy) in a memory and/or a controlunit inside the UE 10. For example, when the timer 1 has expired, the UE10 may execute, based on the policy, one or more of the first to thirdprocedure examples of the third behavior example of the first processingexample and one or more of the first to third procedure examplesperformed after the first processing example, thereby solving such aproblem that the procedure of network slice-specific authentication andauthorization is indefinitely waited.

A processing example that stops the timer 1 being activated will bedescribed below.

It may be set that the UE 10 stops the timer 1 when having received anEAP identity request from the core network or stops the timer 1 whenhaving received EAP success or EAP failure.

A case in which the UE 10 performs movement that involves PLMNinterchange while the timer 1 is activated will be described below.

A PLMN before the interchange is referred to as an interchange sourcePLMN, and a PLMN after the interchange is referred to as an interchangedestination PLMN.

A first procedure example below may be performed as a procedure examplein a case in which the UE 10 performs movement that involves PLMNinterchange while the timer 1 is activated.

It may be set that the timer 1 does not need to be stopped when the UE10 has performed PLMN interchange while the timer 1 is activated. Inthis case, the timer 1 may be managed (stopped or activated) in the unitof third network slice information or in a combination of the unit ofthird network slice information and the unit of UE.

In some instances, the UE 10 may prevent, in the interchange destinationPLMN, transmission of a registration request message (initialregistration request, mobility registration update, or periodicregistration update) using the third network slice information or usingS-NSSAI provided by a serving PLMN to which the third network sliceinformation is mapped in a case in which the interchange source PLMN isa HPLMN.

In some instances, a second procedure example below may be performed asa procedure example in a case in which the UE 10 performs movement thatinvolves PLMN interchange while the timer 1 is activated.

It may be set that the timer 1 does not need to be stopped when the UE10 has performed PLMN interchange while the timer 1 is activated. Inthis case, the timer 1 may be managed (stopped or activated) in the unitof third network slice information or in a combination of the unit ofthird network slice information and the unit of UE. This is to continueactivation of the timer 1, which is activated in the interchange sourcePLMN, when return is made from the interchange destination PLMN to theinterchange source PLMN again through PLMN interchange, therebycontinuously applying registration request message transmissionmanagement applied in the interchange source PLMN.

In some instances, the UE 10 may transmit, in the interchangedestination PLMN, a registration request message (initial registrationrequest, mobility registration update, or periodic registration update)using the third network slice information or using S-NSSAI provided by aserving PLMN to which the third network slice information is mapped in acase in which the interchange source PLMN is a HPLMN.

In some instances, a third procedure example below, which is differentfrom the first and second procedure examples, may be performed as aprocedure example in a case in which the UE 10 performs movement thatinvolves PLMN interchange while the timer 1 is activated.

It may be set that the timer 1 is stopped when the UE 10 has performedPLMN interchange while the timer 1 is activated. The timer 1 may bemanaged (stopped or activated) in the unit of third network sliceinformation and PLMN or in a combination of the unit of third networkslice information, the unit of PLMN, and the unit of UE.

In some instances, the UE 10 may transmit, in the interchangedestination PLMN, a registration request message (initial registrationrequest, mobility registration update, or periodic registration update)using the third network slice information or using S-NSSAI provided by aserving PLMN to which the third network slice information is mapped in acase in which the interchange source PLMN is a HPLMN.

A case in which system interchange is performed from the N1 mode to theS1 mode while the timer 1 is activated will be described below.

A first procedure example below may be performed as a procedure examplein a case in which the UE 10 interchanges the N1 mode with the S1 modewhile the timer 1 is activated.

It may be set that, when the N1 mode is interchanged with the S1 modewhile the timer 1 is activated, the UE 10 does not need to stop thetimer 1 being activated. This is to continue activation of the timer 1,which is initially activated in the N1 mode, in a case of interchangewith the N1 mode again after interchange with the S1 mode, therebycontinuously applying registration request message transmissionmanagement applied in the N1 mode.

In some instances, a second procedure example below, which is differentfrom the first procedure example, may be performed as a procedureexample in a case in which the UE 10 interchanges the N1 mode with theS1 mode while the timer 1 is activated.

It may be set that, when the N1 mode is interchanged with the S1 modewhile the timer 1 is activated, the UE 10 stops the timer 1 beingactivated.

The above description is made on a case in which the UE 10 receives,from the AMF 30, at least one of the third network slice information andthe first reason value, and the first timer information, but thefollowing description will be made on a case in which the UE 10 receivesthe fifth network slice information from the AMF 30.

Specifically, the AMF 30 may transmit the fifth network sliceinformation to the UE 10 when all pieces of S-NSSAI included in thefirst network slice information (requested NSSAI) are targets of networkslice-specific authentication and authorization, when the first networkslice information (requested NSSAI) is not included and all pieces ofdefault S-NSSAI set to the subscriber information are targets of networkslice-specific authentication and authorization, or when all pieces ofS-NSSAI included in the first network slice information (requestedNSSAI) do not match S-NSSAI (subscribed NSSAI) recorded in thesubscriber information and all pieces of default S-NSSAI set to thesubscriber information are targets of network slice-specificauthentication and authorization.

In other words, the AMF 30 transmits the fifth network slice informationsince there is no S-NSSAI as the second network slice information(allowed NSSAI) that can be transmitted to the UE 10. The AMF 30 mayinclude S-NSSAI as a target of network slice-specific authentication andauthorization in the third network slice information and transmit theassociated first reason value (reason value indicating pending) to theUE 10, and does not necessarily need to transmit the third network sliceinformation and the first reason value to the UE 10.

In this case, when having received the first timer information inaddition to the fifth network slice information and at least one of thethird network slice information and the first reason value from the AMF30 as described in the present aspect, the UE 10 may perform behaviorsame as in a case in which the timer 1 is set to the UE in advance.

(Second Aspect)

A second aspect will be described below with reference to FIG. 10.

The present aspect relates to a scenario that, after execution of theprocessing at steps S0501 to S0505 in FIG. 5, the UE 10 receives thethird network slice information including S-NSSAI associated with thefirst reason value and waits the procedure of network slice-specificauthentication and authorization. The UE 10 supports the procedure ofnetwork slice-specific authentication and authorization. The wait of theprocedure of network slice-specific authentication and authorization isa state in which the UE 10 holds one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)after registration accept reception, after registration completionmessage transmission, or after SGMM context establishment. Specifically,the wait of the procedure of network slice-specific authentication andauthorization may mean a case in which no EAP identity request isreceived, neither EAP success nor EAP failure is received, no message(configuration update command or de-registration request) that triggersacquisition of new slice information is received, or no message (DL NAStransport) for setting new slice information is received.

In a solution described below, the UE 10 manages, based on a timer 1and/or a first timer information acquired from the core network or basedon a timer 1 and/or a first timer information set to the UE 10 inadvance, transmission of a registration request (initial registrationrequest, mobility registration update, or periodic registration update)using S-NSSAI associated with the first reason value (reason valueindicating pending). Note that, in the second aspect, unlike the firstaspect, when the timer 1 has stopped or expired, another timer isactivated and registration request transmission management is performed.The management of transmission may mean management of the behavior oftransmission and the behavior of transmission prevention, and thebehavior of transmission is also expressed as re-attempt (reconnection).

A step illustrated in FIG. 10 will be described in detail as follows.

Step (1): after having executed the processing at steps S0501 to S0505in FIG. 5, the UE 10 receives, from the AMF 30, the first timerinformation in addition to at least one of the third network sliceinformation and the first reason value (S1001).

In this case, the UE 10 may hold, in association with the first reasonvalue (reason value indicating pending), one or more pieces of S-NSSAIassociated with the third network slice information. The AMF 30 mayhold, as UE context information in association with the first reasonvalue (reason value indicating pending), one or more pieces of S-NSSAIassociated with the third network slice information. The AMF 30 may holdone or more pieces of S-NSSAI associated with the third network sliceinformation, and/or the first timer information as UE contextinformation in association with the first reason value (reason valueindicating pending).

Step (2): having received the first timer information, the UE 10performs a second processing example (S1002). In the second processingexample, the UE 10 may perform one or more of first to third behaviorexamples. The second processing example includes processing includingbehavior (the first behavior example) that the UE 10 activates the timer1 for determining whether the network is abnormal during the procedureof network slice-specific authentication and authorization, behavior(the second behavior example) until the timer 1 expires or stops, andbehavior (the third behavior example) when the timer 1 has expired orstopped.

The first behavior example in the present aspect may be behavior thatthe UE 10 sets, to the timer 1, a timer value indicated by the firsttimer information or a value set to the UE 10 in advance and activatesthe timer 1. Note that the activation of the timer 1 may mean start ofcounting at the timer. The timer value set to the UE 10 in advance maybe set to the UE 10 so that the timer value is used when the UE 10 islocated in a HPLMN or an equivalent PLMN.

The UE 10 may activate the timer 1 in the unit of one or more pieces ofS-NSSAI associated with the first reason value (reason value indicatingpending) in the third network slice information (rejected NSSAI) or mayactivate the timer 1 in the unit of at least one or a combination ofS-NSSAI, SIM, UE, and PLMN. In other words, the first timer informationincluding the timer value of the timer 1 may be set in the unit of oneor more pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI), or may be set in the unit of at least one or acombination of S-NSSAI, SIM, UE, and PLMN. For example, the UE 10 mayactivate the timer 1 in the unit of one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI), may activatethe timer 1 in the unit of SIM, may activate the timer 1 in the unit ofUE, or may activate the timer 1 in the unit of PLMN. For example, the UE10 may activate the timer 1 in a combination of the unit of one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI) and the unit of PLMN, may activate the timer 1 in a combinationof the unit of one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) and the unit of SIM, ormay activate the timer 1 in a combination of the unit of one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) and the unit of UE. For example, the UE 10 mayactivate the timer 1 in a combination of the unit of SIM and the unit ofPLMN or may activate the timer 1 in a combination of the unit of UE andthe unit of PLMN. For example, the UE 10 may activate the timer 1 in acombination of the unit of one or more pieces of S-NSSAI associated withthe first reason value (reason value indicating pending) in the thirdnetwork slice information (rejected NSSAI), the unit of UE, and the unitof PLMN, may activate the timer 1 in a combination of the unit of one ormore pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI), the unit of SIM, and the unit of PLMN, and mayactivate the timer 1 in a combination of the unit of SIM, the unit ofUE, and the unit of PLMN. For example, the UE 10 may activate the timer1 in a combination of the unit of one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI), the unit ofSIM, the unit of UE, and the unit of PLMN.

Note that, in a case in which there are two or more pieces of S-NSSAIassociated with the first reason value (reason value indicatingpending), the first timer information may be obtained as the product ofthe timer value of a single piece of S-NSSAI and the number of pieces ofS-NSSAI associated with the first reason value (reason value indicatingpending).

The second behavior example in the present aspect may be behavior that,until the timer 1 being activated stops or expires, the UE 10 preventstransmission of a registration request (initial registration request,mobility registration update, or periodic registration update) using oneor more pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI), or S-NSSAI of a serving PLMN to which one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI) are mapped.

The third behavior example in the present aspect may include behaviorthat, when the timer 1 being activated has stopped or expired, the UE 10updates at least one of: one or more pieces of S-NSSAI corresponding tothe first reason value (reason value indicating pending) and/or thethird network slice information (rejected NSSAI).

Specifically, the UE 10 may perform a first procedure example below asthe third behavior example.

When the timer 1 being activated has stopped or expired, the UE 10 maycancel the association of the first reason value (reason valueindicating pending) and one or more pieces of S-NSSAI associated withthe third network slice information (rejected NSSAI), which are held bythe UE 10. The cancellation of the association of the first reason value(reason value indicating pending) and one or more pieces of S-NSSAIassociated with the third network slice information (rejected NSSAI) maymean deletion of the first reason value (reason value indicatingpending) for one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) and the first reason value(reason value indicating pending), which are held by the UE, or may meanrewriting to the second reason value (reason value indicating failure).In this case, the UE 10 may perform rewriting to the second reason value(reason value indicating failure) without message transmission andreception to and from the core network and/or the access network(locally). Note that the deletion of the first reason value (reasonvalue indicating pending) may mean that no reason value is associatedwith the one or more pieces of S-NSSAI.

In some instances, the UE 10 may perform, as the third behavior example,a second procedure example below, which is different from the firstprocedure example.

When the timer 1 being activated has stopped or expired, the UE 10 maydelete one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) in the third network sliceinformation (rejected NSSAI) held by the UE 10. The deletion of one ormore pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI) may mean deletion of both of: the first reason value(reason value indicating pending) held by the UE; and one or more piecesof S-NSSAI associated with the third network slice information (rejectedNSSAI) associated with the first reason value.

In some instances, the UE 10 may perform, as the third behavior example,a third procedure example below, which is different from the first andsecond procedure examples.

In a case in which the UE 10 holds only one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) when the timer 1being activated has stopped or expired, the UE 10 may reset the thirdnetwork slice information (rejected NSSAI), which are held by the UE 10.The resetting of the third network slice information (rejected NSSAI)may mean deletion of all pieces of third network slice information(rejected NSSAI) held by the UE.

In some instances, the UE 10 may perform a first procedure examplebelow, which is performed after the second processing example.

FIG. 11 is a diagram illustrating the procedure of reconnection notusing S-NSSAI that has been associated with the first reason value(reason value indicating pending) in the first procedure exampleperformed after the second processing example of the present aspect.

Specifically, when the timer 1 being activated has stopped or expired asillustrated in FIG. 11, the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message withoutusing one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) in the third network sliceinformation (rejected NSSAI) (S1101). Note that one or more pieces ofS-NSSAI associated with the first reason value (reason value indicatingpending) in the third network slice information (rejected NSSAI) may beone or more pieces of S-NSSAI the associated reason value of which isdeleted or rewritten to the second reason value (reason value indicatingfailure) as described in the first procedure of the third behaviorexample of the second processing example. In this case, the UE 10 mayactivate a timer 2 and/or a timer 3. As written in Section 10.2 of NonPatent Literature 3, the timer 2 may be a mobility timer configured towait a registration accept message from the core network and activatedafter the UE 10 has transmitted a registration request message. Aswritten in Section 10.2 of Non Patent Literature 3, the timer 3 may be atimer configured to manage retransmission of a registration requestmessage.

The AMF 30 receives a registration request message without using one ormore pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI). Subsequently, the AMF 30 may set the second networkslice information to a registration accept message when the secondnetwork slice information that is new (allowed NSSAI) is set to the UE,may set the third network slice information and the second reason valueto a registration accept message when the third network sliceinformation (rejected NSSAI) that is new is set to the UE, may set thefourth network slice information to a registration accept message whenthe fourth network slice information that is new (configured NSSAI) isset to the UE, and may transmit a registration accept message includingthe information to the UE 10 (S1102).

Note that, even when the UE 10 has deleted, or rewritten to the secondreason value (reason value indicating failure), a reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) based on the first procedureexample of the third behavior example of the second processing example,the AMF 30 may recognize, as the first reason value (reason valueindicating pending), the reason value associated as UE contextinformation with the S-NSSAI. In other words, the reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) and recognized by the AMF 30may be different from the reason value associated with one or morepieces of S-NSSAI associated with the third network slice information(rejected NSSAI) and recognized by the UE 10. The reason valuerecognized by the AMF 30 is associated with one or more pieces ofS-NSSAI associated with the third network slice information (rejectedNSSAI).

A case in which the second network slice information is included in aregistration accept message will be described below. When one or morepieces of S-NSSAI included in the second network slice information matchone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) held by the UE 10, the UE 10 may delete the matchingone or more pieces of S-NSSAI from the third network slice information(rejected NSSAI). The UE 10 may transmit, to the AMF 30, a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) message using the one or more pieces ofS-NSSAI deleted from the third network slice information (rejectedNSSAI) (S1103).

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIassociated with the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as the second network sliceinformation, the UE 10 deletes S-NSSAI #1 held as S-NSSAI associatedwith the third network slice information (rejected NSSAI). In addition,the UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using S-NSSAI #1 (S1103).

A case in which the third network slice information and the secondreason value are included in a registration accept message will bedescribed below. When one or more pieces of S-NSSAI included in thethird network slice information match one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) held by the UE10, the UE 10 may rewrite a reason value associated with the matchingone or more pieces of S-NSSAI to a reason value indicated by the secondreason value. The reason value indicated by the second reason value maybe the reason value indicating failure.

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIincluded in the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as S-NSSAI associated with the thirdnetwork slice information and the second reason value (reason valueindicating failure), the UE 10 may rewrite, to the second reason value(reason value indicating failure), the reason value associated withS-NSSAI #1 held as S-NSSAI associated with the third network sliceinformation (rejected NSSAI).

In some instances, for example, when configured NSSAI is included in thefourth network slice information, the UE 10 may delete the held thirdnetwork slice information (rejected NSSAI). In other words, when havingreceived the fourth network slice information (configured NSSAI), the UE10 may reset the held third network slice information (rejected NSSAI).The UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using one or more pieces of S-NSSAIassociated with the fourth network slice information (configured NSSAI)(S1103). The fourth network slice information set by the UE 10 mayinclude one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) for network slice-specificauthentication and authorization in the third network slice information(rejected NSSAI). In other words, at step at S1103, the UE 10 cantransmit a registration request (initial registration request, mobilityregistration update, or periodic registration update) message to the AMF30 by using one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) for networkslice-specific authentication and authorization, which have beenincluded in the reset third network slice information (rejected NSSAI).

For example, it is assumed that the UE 10 holds S-NSSAI #1 and S-NSSAI#2 as S-NSSAI associated with the third network slice information(rejected NSSAI). S-NSSAI #1 is associated with the first reason value(reason value indicating pending). S-NSSAI #2 is associated with thefourth reason value (reason value indicating “S-NSSAI not available inthe current registration area”) disclosed in Non Patent Literature 3. Inthis case, when having received a registration accept message includingthe fourth network slice information (configured NSSAI), the UE 10 maydelete both S-NSSAI #1 and S-NSSAI #2 held as S-NSSAI associated withthe third network slice information (rejected NSSAI) or may delete thethird network slice information (rejected NSSAI) held by the UE 10. Forexample, when S-NSSAI #1 is included in the fourth network sliceinformation (configured NSSAI), the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message usingS-NSSAI #1 included in the fourth network slice information (configuredNSSAI).

In some instances, the UE 10 may perform a second procedure examplebelow, which is performed after the second processing example.

FIG. 12 is a diagram illustrating the procedure of reconnection usingS-NSSAI associated with the first reason value (reason value indicatingpending) in the second procedure example performed after the secondprocessing example of the present aspect.

Specifically, when the timer 1 being activated has stopped or expired asillustrated in FIG. 12, the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message by usingS-NSSAI associated with the first reason value (reason value indicatingpending) in the third network slice information (rejected NSSAI), orS-NSSAI provided by a PLMN to which the S-NSSAI is mapped (S1201). Notethat one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) in the third network sliceinformation (rejected NSSAI) may be one or more pieces of S-NSSAI theassociated reason value of which is deleted or rewritten to the secondreason value (reason value indicating failure) as described in the firstprocedure of the third behavior example of the second processingexample. In this case, the UE 10 may activate a timer 2 and/or a timer3. As written in Section 10.2 of Non Patent Literature 3, the timer 2may be a mobility timer configured to wait a registration accept messagefrom the core network and activated after the UE 10 has transmitted aregistration request message. As written in Section 10.2 of Non PatentLiterature 3, the timer 3 may be a timer configured to manageretransmission of a registration request message.

The AMF 30 receives a registration request message using one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI). Subsequently, the AMF 30 may set the second network sliceinformation to a registration accept message when the second networkslice information that is new (allowed NSSAI) is set to the UE, may setthe third network slice information and the second reason value to aregistration accept message when the third network slice information(rejected NSSAI) that is new is set to the UE, may set the fourthnetwork slice information to a registration accept message when thefourth network slice information that is new (configured NSSAI) is setto the UE, and may transmit a registration accept message including theinformation to the UE 10 (S1202).

Note that, even when the UE 10 has deleted, or rewritten to the secondreason value (reason value indicating failure), a reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) based on the first procedureexample of the third behavior example of the second processing example,the AMF 30 may recognize, as the first reason value (reason valueindicating pending), the reason value associated as UE contextinformation with the S-NSSAI. In other words, the reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) and recognized by the AMF 30may be different from the reason value associated with one or morepieces of S-NSSAI associated with the third network slice information(rejected NSSAI) and recognized by the UE 10.

A case in which the second network slice information is included in aregistration accept message will be described below. When one or morepieces of S-NSSAI included in the second network slice information matchone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) held by the UE 10, the UE 10 may delete the matchingone or more pieces of S-NSSAI from the third network slice information(rejected NSSAI). The UE 10 may transmit, to the AMF 30, a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) message using the one or more pieces ofS-NSSAI deleted from the third network slice information (rejectedNSSAI).

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIassociated with the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as the second network sliceinformation, the UE 10 deletes S-NSSAI #1 held as S-NSSAI associatedwith the third network slice information (rejected NSSAI). In addition,the UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using S-NSSAI #1 (S1203).

A case in which the third network slice information and the secondreason value are included in a registration accept message will bedescribed below. When one or more pieces of S-NSSAI included in thethird network slice information match one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) held by the UE10, the UE 10 may rewrite a reason value associated with the matchingone or more pieces of S-NSSAI to a reason value indicated by the secondreason value. The reason value indicated by the second reason value maybe the reason value indicating failure.

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIassociated with the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as S-NSSAI associated with the thirdnetwork slice information and the second reason value (reason valueindicating failure), the UE 10 may rewrite, to the second reason value(reason value indicating failure), the reason value associated withS-NSSAI #1 held as S-NSSAI associated with the third network sliceinformation (rejected NSSAI).

In some instances, for example, when configured NSSAI is included in thefourth network slice information, the UE 10 may delete the held thirdnetwork slice information (rejected NSSAI). In other words, when havingreceived the fourth network slice information (configured NSSAI), the UE10 may reset the held third network slice information (rejected NSSAI).The UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using one or more pieces of S-NSSAIassociated with the fourth network slice information (configured NSSAI)(S1203). The fourth network slice information set by the UE 10 mayinclude one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) for network slice-specificauthentication and authorization in the third network slice information(rejected NSSAI). In other words, at step at S1203, the UE 10 cantransmit a registration request (initial registration request, mobilityregistration update, or periodic registration update) message to the AMF30 by using one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) for networkslice-specific authentication and authorization, which have beenincluded in the reset third network slice information (rejected NSSAI).

For example, it is assumed that the UE 10 holds S-NSSAI #1 and S-NSSAI#2 as S-NSSAI associated with the third network slice information(rejected NSSAI). S-NSSAI #1 is associated with the first reason value(reason value indicating pending). S-NSSAI #2 is associated with thefourth reason value (reason value indicating “S-NSSAI not available inthe current registration area”) disclosed in Non Patent Literature 3. Inthis case, when having received a registration accept message includingthe fourth network slice information (configured NSSAI), the UE 10 maydelete both S-NSSAI #1 and S-NSSAI #2 held as S-NSSAI associated withthe third network slice information (rejected NSSAI) or may delete thethird network slice information (rejected NSSAI) held by the UE 10. Forexample, when S-NSSAI #1 is included in the fourth network sliceinformation (configured NSSAI), the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message usingS-NSSAI #1 included in the fourth network slice information (configuredNSSAI).

Note that, in the first and second procedure examples performed afterthe second processing example, it is described that, when the timer 1has stopped or expired, the UE 10 transmits a registration request tothe AMF 30 and acquires, through registration accept as a reply to theregistration request, new network slice information (the second networkslice information, the third network slice information and the secondreason value, and/or the fourth network slice information) and activatesthe timer 2 and/or the timer 3. In this manner, the means for solvingsuch a problem that the UE 10 indefinitely waits the procedure ofnetwork slice-specific authentication and authorization is describedabove, but the present invention is not limited thereto.

Specifically, the UE 10 may receive, from the AMF 30, a configurationupdate command including the first instruction information. The UE 10may transmit a registration request message to the AMF 30 based on thefirst instruction information, and the AMF 30 may include the secondnetwork slice information, the third network slice information and thesecond reason value, and/or the fourth network slice information in aregistration accept message in response to the registration requestmessage, thereby setting new network slice information to the UE. Thebehavior of the UE 10 related to registration request transmission andregistration accept may be same as the above-described behavior of theUE 10 in the first and second procedure examples performed after thesecond processing example.

The first to third behaviors of the second processing example may bebehavior executed based on a rule and/or a policy inside the UE 10. TheUE 10 may hold a policy (UE policy) in a memory and/or a control unitinside the UE 10. For example, it may be set that, when the timer 1 hasexpired and a registration request message has been transmitted to theAMF 30, the UE 10 activates the timer 2 and/or the timer 3 based on thepolicy.

A processing example that stops the timer 1 being activated will bedescribed below.

It may be set that the UE 10 stops the timer 1 when having received anEAP identity request from the core network or stops the timer 1 whenhaving received EAP success or EAP failure.

A case in which the UE 10 performs movement that involves PLMNinterchange while the timer 1 is activated will be described below.

A PLMN before the interchange is referred to as an interchange sourcePLMN, and a PLMN after the interchange is referred to as an interchangedestination PLMN.

A first procedure example below may be performed as a procedure examplein a case in which the UE 10 performs movement that involves PLMNinterchange while the timer 1 is activated.

It may be set that the timer 1 does not need to be stopped when the UE10 has performed PLMN interchange while the timer 1 is activated. Inthis case, the timer 1 may be managed (stopped or activated) in the unitof third network slice information or in a combination of the unit ofthird network slice information and the unit of UE.

In some instances, the UE 10 may prevent, in the interchange destinationPLMN, transmission of a registration request message (initialregistration request, mobility registration update, or periodicregistration update) using the third network slice information or usingS-NSSAI provided by a serving PLMN to which the third network sliceinformation is mapped in a case in which the interchange source PLMN isa HPLMN.

In some instances, a second procedure example below may be performed asa procedure example in a case in which the UE 10 performs movement thatinvolves PLMN interchange while the timer 1 is activated.

It may be set that the timer 1 does not need to be stopped when the UE10 has performed PLMN interchange while the timer 1 is activated. Inthis case, the timer 1 may be managed (stopped or activated) in the unitof third network slice information or in a combination of the unit ofthird network slice information and the unit of UE. This is to continueactivation of the timer 1, which is activated in the interchange sourcePLMN, when return is made from the interchange destination PLMN to theinterchange source PLMN again through PLMN interchange, therebycontinuously applying registration request message transmissionmanagement applied in the interchange source PLMN.

In some instances, the UE 10 may transmit, in the interchangedestination PLMN, a registration request message (initial registrationrequest, mobility registration update, or periodic registration update)using the third network slice information or using S-NSSAI provided by aserving PLMN to which the third network slice information is mapped in acase in which the interchange source PLMN is a HPLMN.

In some instances, a third procedure example below, which is differentfrom the first and second procedure examples, may be performed as aprocedure example in a case in which the UE 10 performs movement thatinvolves PLMN interchange while the timer 1 is activated.

It may be set that the timer 1 is stopped when the UE 10 has performedPLMN interchange while the timer 1 is activated. The timer 1 may bemanaged (stopped or activated) in the unit of third network sliceinformation and PLMN or in a combination of the unit of third networkslice information, the unit of PLMN, and the unit of UE.

In some instances, the UE 10 may transmit, in the interchangedestination PLMN, a registration request message (initial registrationrequest, mobility registration update, or periodic registration update)using the third network slice information or using S-NSSAI provided by aserving PLMN to which the third network slice information is mapped in acase in which the interchange source PLMN is a HPLMN.

A case in which system interchange is performed from the N1 mode to theS1 mode while the timer 1 is activated will be described below.

A first procedure example below may be performed as a procedure examplein a case in which the UE 10 interchanges the N1 mode with the S1 modewhile the timer 1 is activated.

It may be set that, when the N1 mode is interchanged with the S1 modewhile the timer 1 is activated, the UE 10 does not need to stop thetimer 1 being activated. This is to continue activation of the timer 1,which is initially activated in the N1 mode, in a case of interchangewith the N1 mode again after interchange with the S1 mode, therebycontinuously applying registration request message transmissionmanagement applied in the N1 mode.

In some instances, a second procedure example below, which is differentfrom the first procedure example, may be performed as a procedureexample in a case in which the UE 10 interchanges the N1 mode with theS1 mode while the timer 1 is activated.

It may be set that, when the N1 mode is interchanged with the S1 modewhile the timer 1 is activated, the UE 10 stops the timer 1 beingactivated.

The above description is made on a case in which, after having executedthe processing at steps S0501 to S0505 in FIG. 5, the UE 10 receives,from the AMF 30, at least one of the third network slice information andthe first reason value, and the first timer information, but thefollowing description will be made on a case in which the fifth networkslice information is received.

Specifically, the AMF 30 may transmit the fifth network sliceinformation in place of the second network slice information to the UE10 when all pieces of S-NSSAI included in the first network sliceinformation (requested NSSAI) are targets of network slice-specificauthentication and authorization, when the first network sliceinformation (requested NSSAI) is not included and all pieces of defaultS-NSSAI set to the subscriber information are targets of networkslice-specific authentication and authorization, or when all pieces ofS-NSSAI included in the first network slice information (requestedNSSAI) do not match S-NSSAI (subscribed NSSAI) recorded in thesubscriber information and all pieces of default S-NSSAI set to thesubscriber information are targets of network slice-specificauthentication and authorization.

In other words, the AMF 30 transmits the fifth network slice informationsince there is no S-NSSAI as the second network slice information(allowed NSSAI) that can be transmitted to the UE 10. The AMF 30 mayinclude S-NSSAI as a target of network slice-specific authentication andauthorization in the third network slice information and transmit theassociated first reason value (reason value indicating pending) to theUE 10, and does not necessarily need to transmit the third network sliceinformation and the first reason value to the UE 10.

In this case, when having received the first timer information inaddition to at least one of the third network slice information and thefirst reason value from the AMF 30 as described in the present aspect,the UE 10 may perform behavior same as in a case in which the timer 1 isset to the UE in advance.

(Third Aspect)

A third aspect will be described below with reference to FIG. 13.

The present aspect relates to a scenario that, after execution of theprocessing at steps S0501 to S0505 in FIG. 5, the UE 10 receives thethird network slice information including S-NSSAI associated with thefirst reason value and waits the procedure of network slice-specificauthentication and authorization. The UE 10 supports the procedure ofnetwork slice-specific authentication and authorization. The wait of theprocedure of network slice-specific authentication and authorization isa state in which the UE 10 holds one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)after registration accept reception, after registration completionmessage transmission, or after SGMM context establishment. Specifically,the wait of the procedure of network slice-specific authentication andauthorization may mean a case in which no EAP identity request isreceived, neither EAP success nor EAP failure is received, no message(configuration update command or de-registration request) that triggersacquisition of new slice information is received, or no message (DL NAStransport) for setting new slice information is received.

In a solution described below, the UE 10 manages, based on a timer 11activated by the core network, transmission of a registration request(initial registration request, mobility registration update, or periodicregistration update) using S-NSSAI associated with the first reasonvalue (reason value indicating pending). Note that the management oftransmission may mean management of the behavior of transmission and thebehavior of transmission prevention, and the behavior of transmission isalso expressed as re-attempt (reconnection).

The timer 11 may be a timer activated when the core network transmits,to the UE 10, a registration accept message using the third networkslice information and S-NSSAI associated with the first reason value. Inother words, the timer 11 may be a timer for determining whether thenetwork is abnormal during the procedure of network slice-specificauthentication and authorization.

A step illustrated in FIG. 13 will be described in detail as follows.

Step (1): after having executed the processing at steps S0501 to S0505in FIG. 5, the AMF 30 transmits at least one of the third network sliceinformation and the first reason value to the UE 10 (S1301). Thetransmission of at least one of the third network slice information andthe first reason value may be performed upon reception of a registrationcomplete message from the UE 10 by the AMF 30 at Step (1).

In this case, the UE 10 may hold one or more pieces of S-NSSAI indicatedby the third network slice information in association with the firstreason value (reason value indicating pending). The AMF 30 may hold oneor more pieces of S-NSSAI corresponding to the third network sliceinformation as UE context information in association with the firstreason value (reason value indicating pending). The AMF 30 may hold, asUE context information, one or more pieces of S-NSSAI associated withthe third network slice information, and/or a timer value set to thetimer 11 in association with the first reason value (reason valueindicating pending).

Step (2): the AMF 30 performs a third processing example (S1302). In thethird processing example, the AMF 30 may perform one or more of a firstbehavior example, a second behavior example, and a third behaviorexample. The third processing example includes processing includingbehavior (the first behavior example) that the AMF 30 activates thetimer 11 for determining whether the network is abnormal during theprocedure of network slice-specific authentication and authorization,behavior (the second behavior example) until the timer 11 expires orstops, and behavior (the third behavior example) when the timer 11 hasexpired or stopped.

The first behavior example in the present aspect may be behavior thatthe AMF 30 activates the timer 11.

The AMF 30 may activate the timer 11 in the unit of one or more piecesof S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI), and/or in the unit of UE, and/or in the unit of PLMN, or in acombination thereof. In other words, the first timer informationincluding the timer value of the timer 11 may be set in the unit of oneor more pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI), and/or in the unit of UE, and/or in the unit of PLMN,or in a combination thereof. For example, the AMF 30 may activate thetimer 11 in the unit of one or more pieces of S-NSSAI associated withthe first reason value (reason value indicating pending) in the thirdnetwork slice information (rejected NSSAI), may activate the timer 11 ina combination of the unit of one or more pieces of S-NSSAI associatedwith the first reason value (reason value indicating pending) in thethird network slice information (rejected NSSAI) and the unit of PLMN,may activate the timer 11 in a combination of the unit of one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI), the unit of UE, and the unit of PLMN, may activate the timer 11in the unit of UE, may activate the timer 11 in the unit of PLMN, mayactivate the timer 11 in a combination of the unit of UE and the unit ofPLMN, or may activate the timer 11 in a combination of the unit of oneor more pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI) and the unit of UE.

Note that, in a case in which there are two or more pieces of S-NSSAIassociated with the first reason value (reason value indicatingpending), a timer value set to the timer 11 may be obtained as theproduct of the timer value of a single piece of S-NSSAI and the numberof pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending).

A procedure example 1 below may be performed as the second behaviorexample in the present aspect.

Until the timer 11 being activated stops or expires, the AMF 30 mayignore one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) in the third network sliceinformation (rejected NSSAI) received from the UE 10, or a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) using S-NSSAI of a serving PLMN to whichone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) are mapped.

The AMF 30 may perform a procedure example 2 below as the secondbehavior example.

Until the timer 11 being activated stops or expires, when havingreceived, from the UE 10, one or more pieces of S-NSSAI associated withthe first reason value (reason value indicating pending) in the thirdnetwork slice information (rejected NSSAI), or a registration request(initial registration request, mobility registration update, or periodicregistration update) using S-NSSAI of a serving PLMN to which one ormore pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI) are mapped, the AMF 30 may transmit a registrationreject message to which a reason value (reject cause) for each S-NSSAIis set or a registration accept message to the UE 10 in accordance withthe processing situation of the procedure of network slice-specificauthentication and authorization for the S-NSSAI. The reject cause maybe, for example, Network Slice specific authentication and authorizationon going, AAA server not responding, AAA server failure, or AAA servernot found.

A procedure example 3 below may be performed as the second behaviorexample in the present aspect.

Until the timer 11 being activated stops or expires, when havingreceived, from the SMF 40, one or more pieces of S-NSSAI associated withthe first reason value (reason value indicating pending) in the thirdnetwork slice information (rejected NSSAI), or aNamf_Communication_N1N2MessageTransfer message for S-NSSAI of a servingPLMN to which one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) in the third networkslice information (rejected NSSAI) are mapped, the AMF 30 may setinformation indicating that the procedure of network slice-specificauthentication and authorization is in execution for the S-NNSAI and maytransmit a Namf_Communication_N1N2MessageTransfer response message tothe SMF 40. The information indicating that the procedure of networkslice-specific authentication and authorization in is execution for theS-NNSAI may include information (temporally not available) notifyingthat the Namf_Communication_N1N2MessageTransfer message temporarilycannot be processed. The SMF 40 receives the information indicating thatthe procedure of network slice-specific authentication and authorizationis in execution for the S-NNSAI. Subsequently, the SMF 40 may activate aunique timer (locally configured timer) and retransmit theNamf_Communication_N1N2MessageTransfer message to the AMF 40 after acertain duration.

The third behavior example in the present aspect may include behaviorthat the AMF 30 cancels the association of the first reason value(reason value indicating pending) and one or more pieces of S-NSSAIassociated with the third network slice information (rejected NSSAI),which are held as UE context information in the UE 10 at thetransmission destination of a configuration update command, ade-registration request message, or a DL NAS transport message. Thecancellation of the association of the first reason value (reason valueindicating pending) and one or more pieces of S-NSSAI associated withthe third network slice information (rejected NSSAI) may mean deletionof the first reason value (reason value indicating pending) among one ormore pieces of S-NSSAI associated with the third network sliceinformation (rejected NSSAI) and the first reason value (reason valueindicating pending) held by the AMF 30 or may mean rewriting to thesecond reason value (reason value indicating failure).

Step (3): after the third processing example, behavior that the AMF 30transmits a configuration update command, a de-registration requestmessage, or a DL NAS transport message to the UE 10 (S1303/S1304/S1305)may be performed for the UE 10 to solve such a problem that theprocedure of network slice-specific authentication and authorization isindefinitely waited. These messages may be transmitted to set newnetwork slice information to the UE 10. The new network sliceinformation may be the second network slice information (allowed NSSAI),the third network slice information (rejected NSSAI), and/or the fourthnetwork slice information (configured NSSAI).

Specifically, the AMF 30 may perform, as Step (3) performed after thethird processing example, a first procedure example illustrated in (A)in FIG. 13 as follows.

When the timer 11 being activated has stopped or expired, the AMF 30 mayset the first instruction information, the third network sliceinformation, and/or the first reason value to a de-registration requestand may transmit the de-registration request to the UE 10 (S1303).Re-registration required or another information element may be set tothis de-registration request message, and through transmission of themessage, the AMF may prompt the UE 10 to activate re-registrationprocessing.

In some instances, the AMF 30 may perform, as Step (3) performed afterthe third processing example, a second procedure example illustrated in(B) in FIG. 13, which is different from the first procedure example, asfollows.

When the timer 11 being activated has stopped or expired, the AMF 30 mayset the first instruction information, the second network sliceinformation, the third network slice information, and/or the firstreason value to a configuration update command and may transmit theconfiguration update command to the UE 10 (S1304). Re-registrationrequired or another information element may be set to this configurationupdate command message, and through transmission of the message, the AMF30 may prompt the UE 10 to activate re-registration processing.

In some instances, the AMF 30 may perform, as Step (3) performed afterthe third processing example, a third procedure example illustrated in(C) in FIG. 13, which is different from the first and second procedureexamples, as follows.

When the timer 11 being activated has stopped or expired, the AMF 30 mayset the second network slice information, the third network sliceinformation, the first reason value, and/or the fourth network sliceinformation to a DL NAS transport message and may transmit the DL NAStransport message to the UE 10 (S1305). Re-registration required oranother information element may be set to the DL NAS transport message,and through transmission of the message, the AMF 30 may prompt the UE 10to activate re-registration processing.

Having received the message described above in the first procedureexample, the second procedure example, or the third procedure example inthe present aspect, the UE 10 performs a fourth processing example. Inthe fourth processing example, the UE 10 may perform a first behaviorexample.

Specifically, the UE 10 may perform a first procedure example below asthe first behavior example.

When the UE 10 has received the second network slice information and oneor more pieces of S-NSSAI included in the second network sliceinformation match one or more pieces of S-NSSAI associated with thefirst reason value (reason value indicating pending) in the thirdnetwork slice information (rejected NSSAI) held by the UE 10, the UE 10may delete the matching one or more pieces of S-NSSAI from the thirdnetwork slice information (rejected NSSAI).

In some instances, the UE 10 may perform a second procedure examplebelow as the first behavior example.

When the UE 10 has received the third network slice information and thesecond reason value and one or more pieces of S-NSSAI included in thethird network slice information match one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) held by the UE10, the UE 10 may rewrite a reason value associated with the matchingone or more pieces of S-NSSAI to a reason value indicated by the secondreason value. The reason value indicated by the second reason value maybe the reason value indicating failure.

In some instances, the UE 10 may perform a third procedure example belowas the first behavior example.

When having received the fourth network slice information includingconfigured NSSAI, the UE 10 may delete the held third network sliceinformation (rejected NSSAI). In other words, the UE 10 may reset theheld third network slice information (rejected NSSAI) by receiving thefourth network slice information (configured NSSAI). The UE 10 maytransmit, to the AMF 30, a registration request (initial registrationrequest, mobility registration update, or periodic registration update)message using one or more pieces of S-NSSAI associated with the fourthnetwork slice information (configured NSSAI). The fourth network sliceinformation set by the UE 10 may include one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)for network slice-specific authentication and authorization in the thirdnetwork slice information (rejected NSSAI). In other words, the UE 10can transmit a registration request (initial registration request,mobility registration update, or periodic registration update) messageto the AMF 30 by using one or more pieces of S-NSSAI associated with thefirst reason value (reason value indicating pending) for networkslice-specific authentication and authorization, which have beenincluded in the reset third network slice information (rejected NSSAI).

In some instances, after the fourth processing example, the UE 10 mayperform a first procedure example below as the second behavior example.The first procedure example in the second behavior example may beperformed in addition to the first procedure example, the secondprocedure example, or the third procedure example in the first behaviorexample.

FIG. 14 is a diagram illustrating the procedure of reconnection withoutusing S-NSSAI associated with the first reason value (reason valueindicating pending) in the first procedure example of the secondbehavior example in the present aspect.

Specifically, after having performed the fourth processing example inthe present aspect as illustrated in FIG. 14, the UE 10 may transmit, tothe AMF 30, a registration request (initial registration request,mobility registration update, or periodic registration update) messagewithout using one or more pieces of S-NSSAI corresponding to the firstreason value (reason value indicating pending) in the third networkslice information (rejected NSSAI) (S1401).

One or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) may be, for example, S-NSSAI the reason value of whichis rewritten to the second reason value (reason value indicatingfailure), which is described in the first behavior example of the fourthprocessing example according to the present aspect.

The AMF 30 receives a registration request message without using one ormore pieces of S-NSSAI associated with the first reason value (reasonvalue indicating pending) in the third network slice information(rejected NSSAI). Subsequently, the AMF 30 may set the second networkslice information to a registration accept message when the secondnetwork slice information that is new (allowed NSSAI) is set to the UE,may set the third network slice information and the second reason valueto a registration accept message when the third network sliceinformation (rejected NSSAI) that is new is set to the UE, may set thefourth network slice information to a registration accept message whenthe fourth network slice information that is new (configured NSSAI) isset to the UE, and may transmit a registration accept message includingthe information to the UE 10 (S1402).

A case in which the second network slice information is included in aregistration accept message will be described below. When one or morepieces of S-NSSAI included in the second network slice information matchone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) held by the UE 10, the UE 10 may delete the matchingone or more pieces of S-NSSAI from the third network slice information(rejected NSSAI). The UE 10 may transmit, to the AMF 30, a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) message using the one or more pieces ofS-NSSAI deleted from the third network slice information (rejectedNSSAI) (S1403).

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIassociated with the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as the second network sliceinformation, the UE 10 deletes S-NSSAI #1 held as S-NSSAI associatedwith the third network slice information (rejected NSSAI). In addition,the UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using S-NSSAI #1 (S1403).

A case in which the third network slice information and the secondreason value are included in a registration accept message will bedescribed below. When one or more pieces of S-NSSAI included in thethird network slice information match one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) held by the UE10, the UE 10 may rewrite a reason value associated with the matchingone or more pieces of S-NSSAI to a reason value indicated by the secondreason value. The reason value indicated by the second reason value maybe the reason value indicating failure.

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIassociated with the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as the third network sliceinformation and the second reason value (reason value indicatingfailure), the UE 10 may rewrite, to the second reason value (reasonvalue indicating failure), the reason value associated with S-NSSAI #1held as S-NSSAI associated with the third network slice information(rejected NSSAI).

In some instances, for example, when configured NSSAI is included in thefourth network slice information, the UE 10 may delete the held thirdnetwork slice information (rejected NSSAI). In other words, when havingreceived the fourth network slice information (configured NSSAI), the UE10 may reset the held third network slice information (rejected NSSAI).The UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using one or more pieces of S-NSSAIassociated with the fourth network slice information (configured NSSAI)(S1403). The fourth network slice information set by the UE 10 mayinclude one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) for network slice-specificauthentication and authorization in the third network slice information(rejected NSSAI). In other words, at step S1403, the UE 10 can transmita registration request (initial registration request, mobilityregistration update, or periodic registration update) message to the AMF30 by using one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) for networkslice-specific authentication and authorization, which have beenincluded in the reset third network slice information (rejected NSSAI).

For example, it is assumed that the UE 10 holds S-NSSAI #1 and S-NSSAI#2 as S-NSSAI associated with the third network slice information(rejected NSSAI). S-NSSAI #1 is associated with the first reason value(reason value indicating pending). S-NSSAI #2 is associated with thefourth reason value (reason value indicating “S-NSSAI not available inthe current registration area”) disclosed in Non Patent Literature 3. Inthis case, when having received a registration accept message includingthe fourth network slice information (configured NSSAI), the UE 10 maydelete both S-NSSAI #1 and S-NSSAI #2 held as S-NSSAI associated withthe third network slice information (rejected NSSAI) or may delete thethird network slice information (rejected NSSAI) held by the UE 10. Forexample, when S-NSSAI #1 is included in the fourth network sliceinformation (configured NSSAI), the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message usingS-NSSAI #1 included in the fourth network slice information (configuredNSSAI).

In some instances, after the fourth processing example, the UE 10 mayperform a second procedure example below as the second behavior example.

FIG. 15 is a diagram illustrating the procedure of reconnection usingS-NSSAI associated with the first reason value (reason value indicatingpending) in the second procedure example of the second behavior examplein the present aspect.

Specifically, after having performed the fourth processing example inthe present aspect as illustrated in FIG. 15, the UE 10 may transmit, tothe AMF 30, a registration request (initial registration request,mobility registration update, or periodic registration update) messageusing one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) in the third network sliceinformation (rejected NSSAI) (S1501).

The AMF 30 receives a registration request message using one or morepieces of S-NSSAI associated with the first reason value (reason valueindicating pending) in the third network slice information (rejectedNSSAI). Subsequently, the AMF 30 may set the second network sliceinformation to a registration accept message when the second networkslice information that is new (allowed NSSAI) is set to the UE, may setthe third network slice information and the second reason value to aregistration accept message when the third network slice information(rejected NSSAI) that is new is set to the UE, may set the fourthnetwork slice information to a registration accept message when thefourth network slice information that is new (configured NSSAI) is setto the UE, and may transmit a registration accept message including theinformation to the UE 10 (S1502).

Note that, even when the UE 10 has deleted, or rewritten to the secondreason value (reason value indicating failure), a reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) based on the first procedureexample, the AMF 30 may recognize, as the first reason value (reasonvalue indicating pending), the reason value associated as UE contextinformation with the S-NSSAI. In other words, the reason valuerecognized by the AMF 30 may be different from the reason valueassociated with one or more pieces of S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI) recognized by the UE 10. Thereason value recognized by the AMF 30 is associated with one or morepieces of S-NSSAI associated with the recognized third network sliceinformation (rejected NSSAI).

A case in which the second network slice information is included in aregistration accept message will be described below. When one or morepieces of S-NSSAI included in the second network slice information matchone or more pieces of S-NSSAI associated with the first reason value(reason value indicating pending) in the third network slice information(rejected NSSAI) held by the UE 10, the UE 10 may delete the matchingone or more pieces of S-NSSAI from the third network slice information(rejected NSSAI). The UE 10 may transmit, to the AMF 30, a registrationrequest (initial registration request, mobility registration update, orperiodic registration update) message using the one or more pieces ofS-NSSAI deleted from the third network slice information (rejectedNSSAI) (S1503).

For example, it is assumed that the UE 10 holds S-NSSAI #1 as S-NSSAIassociated with the third network slice information (rejected NSSAI).S-NSSAI #1 is associated with the first reason value (reason valueindicating pending). In this case, when having received a registrationaccept message including S-NSSAI #1 as the second network sliceinformation, the UE 10 deletes S-NSSAI #1 held as S-NSSAI associatedwith the third network slice information (rejected NSSAI). In addition,the UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using S-NSSAI #1 (S1503).

A case in which the third network slice information and the secondreason value are included in a registration accept message will bedescribed below. When one or more pieces of S-NSSAI included in thethird network slice information match one or more pieces of S-NSSAIassociated with the first reason value (reason value indicating pending)in the third network slice information (rejected NSSAI) held by the UE10, the UE 10 may rewrite a reason value associated with the matchingone or more pieces of S-NSSAI to a reason value indicated by the secondreason value. The reason value indicated by the second reason value maybe the reason value indicating failure.

For example, it is assumed that the UE 10 holds S-NSSAI #1 as the thirdnetwork slice information (rejected NSSAI). S-NSSAI #1 is associatedwith the first reason value (reason value indicating pending). In thiscase, when having received a registration accept message includingS-NSSAI #1 as the third network slice information and the second reasonvalue (reason value indicating failure), the UE 10 may rewrite, to thesecond reason value (reason value indicating failure), the reason valueassociated with S-NSSAI #1 held as S-NSSAI associated with the thirdnetwork slice information (rejected NSSAI).

In some instances, for example, when configured NSSAI is included in thefourth network slice information, the UE 10 may delete the held thirdnetwork slice information (rejected NSSAI). In other words, when havingreceived the fourth network slice information (configured NSSAI), the UE10 may reset the held third network slice information (rejected NSSAI).The UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) message using one or more pieces of S-NSSAIassociated with the fourth network slice information (configured NSSAI)(S1503). The fourth network slice information set by the UE 10 mayinclude one or more pieces of S-NSSAI associated with the first reasonvalue (reason value indicating pending) for network slice-specificauthentication and authorization in the third network slice information(rejected NSSAI). In other words, at step S1503, the UE 10 can transmita registration request (initial registration request, mobilityregistration update, or periodic registration update) message to the AMF30 by using one or more pieces of S-NSSAI associated with the firstreason value (reason value indicating pending) for networkslice-specific authentication and authorization, which are included inthe reset third network slice information (rejected NSSAI).

For example, it is assumed that the UE 10 holds S-NSSAI #1 and S-NSSAI#2 as the third network slice information (rejected NSSAI). S-NSSAI #1is associated with the first reason value (reason value indicatingpending). S-NSSAI #2 is associated with the fourth reason value (reasonvalue indicating “S-NSSAI not available in the current registrationarea”) disclosed in Non Patent Literature 3. In this case, when havingreceived a registration accept message including the fourth networkslice information (configured NSSAI), the UE 10 may delete both S-NSSAI#1 and S-NSSAI #2 held as S-NSSAI associated with the third networkslice information (rejected NSSAI) or may delete the third network sliceinformation (rejected NSSAI) held by the UE 10. For example, whenS-NSSAI #1 is included in the fourth network slice information(configured NSSAI), the UE 10 may transmit, to the AMF 30, aregistration request (initial registration request, mobilityregistration update, or periodic registration update) message usingS-NSSAI #1 included in the fourth network slice information (configuredNSSAI).

Subsequently, a processing example that stops the timer 11 beingactivated will be described below.

It may be set that the AMF 30 stops the timer 11 when having transmittedan EAP identity request to the UE 10 or stops the timer 11 when havingtransmitted EAP success or EAP failure to the UE 10.

The above description is made on a case in which, after having executedthe processing at steps S0501 to S0505 in FIG. 5, the UE 10 receives atleast one of the third network slice information and the first reasonvalue from the AMF 30, but the following description will be made on acase in which the fifth network slice information is received.

Specifically, the AMF 30 may transmit the fifth network sliceinformation to the UE 10 when all pieces of S-NSSAI included in thefirst network slice information (requested NSSAI) are targets of networkslice-specific authentication and authorization, when the first networkslice information (requested NSSAI) is not included and all pieces ofdefault S-NSSAI set to the subscriber information are targets of networkslice-specific authentication and authorization, or when all pieces ofS-NSSAI included in the first network slice information (requestedNSSAI) do not match S-NSSAI (subscribed NSSAI) recorded in thesubscriber information and all pieces of default S-NSSAI set to thesubscriber information are targets of network slice-specificauthentication and authorization.

In this case, the AMF 30 transmits the fifth network slice informationsince there is no S-NSSAI as the second network slice information(allowed NSSAI) that can be transmitted to the UE 10. The AMF 30 mayinclude S-NSSAI as a target of network slice-specific authentication andauthorization in the third network slice information and transmit theassociated first reason value (reason value indicating pending) to theUE 10, does not necessarily need to transmit the third network sliceinformation and the first reason value to the UE 10.

In this case, the UE 10 may perform behavior same as in the case ofhaving received at least one of the third network slice information andthe first reason value from the AMF 30 as described in the presentaspect. Alternatively, the UE 10 may perform behavior same as in thecase of having received the sixth network slice information from the AMF30 as described in the present aspect.

(Fourth Aspect)

A fourth aspect will be described below with reference to FIG. 16.

The present aspect relates to a scenario that, after execution of theprocessing at steps S0501 to S0505 in FIG. 5, the UE 10 receives thethird network slice information including S-NSSAI associated with thefirst reason value and moves to another registration area, whichinvolves change of a serving AMF, while waiting the procedure of networkslice-specific authentication and authorization. The UE 10 supports theprocedure of network slice-specific authentication and authorization.The wait of the procedure of network slice-specific authentication andauthorization is a state in which the UE 10 holds one or more pieces ofS-NSSAI associated with the first reason value (reason value indicatingpending) after registration accept reception, after registrationcomplete message transmission, or after SGMM context establishment.Specifically, the wait of the procedure of network slice-specificauthentication and authorization may mean a case in which no EAPidentity request is received, neither EAP success nor EAP failure isreceived, no message (configuration update command or de-registrationrequest) that triggers acquisition of new slice information is received,or no message (DL NAS transport) for setting new slice information isreceived. An AMF before change is referred to as an old AMF, and an AMFafter change is referred to as a new AMF in some cases.

In a solution described below, even when change of a serving AMF hasoccurred, the UE 10 manages transmission of a registration request(initial registration request, mobility registration update, or periodicregistration update) using S-NSSAI associated with the first reasonvalue (reason value indicating pending) by transmitting and receiving UEcontext information related to the procedure of network slice-specificauthentication and authorization between the old AMF and the new AMF.Note that the management of transmission may mean management of thebehavior of transmission and the behavior of transmission prevention,and the behavior of transmission is also expressed as re-attempt(reconnection).

Steps illustrated in FIG. 16 will be described in detail as follows.

Step (1): after having executed the processing at steps S0501 to S0505in FIG. 5, the UE 10 receives the third network slice information and atleast one of the first reason value, the second reason value, the thirdreason value, or the fourth reason value from the AMF 30 (S1602).

In this case, when transmitting the third network slice information(rejected NSSAI) to the UE 10, the AMF 30 may configure a reason valueassociated therewith as described below.

Specifically, the AMF 30 may configure one information element bycombining at least one of the first reason value, the second reasonvalue, the third reason value, and the fourth reason value with S-NSSAIincluded in the third network slice information. In other words, reasonvalues combined with S-NSSAI included in the third network sliceinformation may be one information element.

Alternatively, the AMF 30 may configure two or more information elementsby combining at least one of the first reason value, the second reasonvalue, the third reason value, and the fourth reason value with S-NSSAIincluded in the third network slice information. For example, eachinformation element may be a combination of the first reason value andthe second reason value, a combination of the first reason value and thethird reason value, or a combination of the first reason value and thefourth reason value. In other words, reason values combined with S-NSSAIincluded in the third network slice information may be two or moreinformation elements.

For example, the UE 10 receives the third network slice informationincluding S-NSSAI associated with a reason value as a combination of thefirst reason value and the fourth reason value. The UE 10 may hold oneor more pieces of S-NSSAI associated with the third network sliceinformation in association with the first reason value (reason valueindicating pending) and the fourth reason value (reason value indicating“S-NSSAI not available in the current registration area”). The AMF 30may hold, as UE context information, one or more pieces of S-NSSAIassociated with the third network slice information in association withthe first reason value (reason value indicating pending) and the fourthreason value (reason value indicating “S-NSSAI not available in thecurrent registration area”).

The UE 10 performs a fifth processing example. The fifth processingexample in the present aspect may be behavior that transmission of aregistration request (initial registration request, mobilityregistration update, or periodic registration update) is managed basedon a reason value associated with S-NSSAI included in the third networkslice information.

For example, when the reason value associated with S-NSSAI included inthe third network slice information is a combination (referred to as acombined reason value) of a reason value indicated by the first reasonvalue and a reason value indicated by the fourth reason value, the UE 10may manage transmission of a registration request (initial registrationrequest, mobility registration update, or periodic registration update)using one or more pieces of S-NSSAI associated with the combined reasonvalue or S-NSSAI of a serving PLMN to which one or more pieces ofS-NSSAI associated with the combined reason value are mapped, until thecombined reason value is canceled.

The UE 10 may perform a first procedure example below. In descriptionwith a more specific example, it is assumed that S-NSSAI #1 is includedin the third network slice information. It is also assumed that S-NSSAI#1 is associated with the first reason value (reason value indicatingpending) and the fourth reason value (reason value indicating “S-NSSAInot available in the current registration area”). It is also assumedthat the procedure of network slice-specific authentication andauthorization is successful. Note that the case in which the procedureof network slice-specific authentication and authorization is successfulmay mean a case in which the UE 10 receives EAP success. In this case,among the reason value indicated by the first reason value and thereason value indicated by the fourth reason value, which are associatedwith S-NSSAI #1 included in the third network slice information held bythe UE 10, the reason value indicated by the first reason value iscanceled, but the reason value indicated by the fourth reason value isnot canceled. Thus, the UE 10 may be prevented from transmitting aregistration request (initial registration request, mobilityregistration update, or periodic registration update) using S-NSSAI #1associated with the combined reason value or S-NSSAI of a serving PLMNto which S-NSSAI #1 associated with the combined reason value is mapped.

The UE 10 may perform a second procedure example below. The secondprocedure example may correspond to a case in which the UE 10 moves toanother registration area, which involves change of a serving AMF.

In description with a more specific example, it is assumed that S-NSSAI#1 is included in the third network slice information. It is alsoassumed that S-NSSAI #1 is associated with the first reason value(reason value indicating pending) and the fourth reason value (reasonvalue indicating “S-NSSAI not available in the current registrationarea”). When the UE 10 moves to another registration area, the reasonvalue of the fourth reason value is canceled, but the reason valueindicated by the first reason value is not canceled. Thus, the UE 10 maybe prevented from transmitting a registration request (initialregistration request, mobility registration update, or periodicregistration update) using S-NSSAI #1 associated with the combinedreason value or S-NSSAI of a serving PLMN to which S-NSSAI #1 associatedwith the combined reason value is mapped.

A preliminary operation example of the AMF 30 for achieving the secondprocedure example of the fifth processing example will be describedbelow.

As for the registration area movement of the UE 10, which is describedin the second procedure example, a registration area before the movementis referred to as RA1, and a registration area after the movement isreferred to as RA2. It is assumed that the core network is configured sothat an AMF 30 (referred to as an old AMF 30) configured to transmit andreceive messages through RA1 is different from an AMF 30 (referred to asa new AMF 30) configured to transmit and receive messages through RA2.

The new AMF 30 having received a registration request (mobilityregistration update) message transmitted when the UE 10 has moved fromRA1 to RA2 acquires UE context information related to networkslice-specific authentication and authorization from the old AMF 30(S1601).

Specifically, the new AMF 30 may activate anNamf_Communication_UEContextTransfer function disclosed in Non PatentLiterature 1 or a service and may request the execution state of theprocedure of network slice-specific authentication and authorizationfrom the old AMF 30. The old AMF 30, from which the execution state ofthe procedure of network slice-specific authentication and authorizationis requested, may respond the execution state of the procedure ofnetwork slice-specific authentication and authorization related to theUE 10. When having acquired the execution state of the procedure ofnetwork slice-specific authentication and authorization related to theUE 10, the new AMF 30 may execute the procedure of networkslice-specific authentication and authorization related to the UE 10.The execution of the procedure of network slice-specific authenticationand authorization may be processing that determines execution of theprocedure of network slice-specific authentication and authorizationperformed by the AMF 30, which is described with reference to FIG. 6, ormay be processing that executes the EAP (extensible authenticationprotocol)-utilized procedure of network slice-specific authenticationand authorization written in Section 4.2.9.2 of Non Patent Literature 2,which is described for the procedure of network slice-specificauthentication and authorization.

Specifically, the new AMF 30 may perform processing that transmits,toward the UE 10, an EAP identity request based on the UE contextinformation related to network slice-specific authentication andauthorization, which is acquired by the old AMF 30.

Thus, the AMF 30 can perform, as management of the state of networkslice-specific authentication and authorization, management of the stateof pending in addition to management of the states of success andfailure.

The new AMF 30 transmits the third network slice information and atleast one of the first reason value, the second reason value, the thirdreason value, and the fourth reason value to the UE 10 (S1602).Thereafter, the UE 10 performs the fifth processing example.

In a specific example in the first procedure example of the fifthprocessing example, the reason value of the fourth reason value iscanceled when the UE 10 has moved to another registration area. Thus,the UE 10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) using S-NSSAI #1 associated with the combinedreason value or S-NSSAI of a serving PLMN to which S-NSSAI #1 associatedwith the combined reason value is mapped (S1603).

Thus, the reason value indicated by the first reason value may be areason value that does not depend on a registration area, and once theprocedure of network slice-specific authentication and authorization issuccessful, the state in which the procedure of network slice-specificauthentication and authorization is successful may be maintained evenwhen change to another registration area has occurred. Note that the UE10 may hold, in association with the S-NSSAI, the state in which theprocedure of network slice-specific authentication and authorization issuccessful, and specifically, may hold the state in association with thereason value indicating success.

In a specific example in the second procedure example of the fifthprocessing example, the reason value of the fourth reason value iscanceled when the UE 10 has moved to another registration area. However,the first reason value is not canceled, and thus the UE 10 may beprevented from transmitting a registration request (initial registrationrequest, mobility registration update, or periodic registration update)using S-NSSAI #1 associated with the combined reason value or S-NSSAI ofa serving PLMN to which S-NSSAI #1 associated with the combined reasonvalue is mapped.

Thus, the reason value indicated by the first reason value may be areason value that does not depend on a registration area, S-NSSAI oncesubjected to pending may be maintained in the state of pending even whenchange to another registration area has occurred. Note that the UE 10may hold the state of pending in association with the S-NSSAI, andspecifically, may hold in association with the reason value indicatingpending.

It is assumed that, thereafter, the procedure of network slice-specificauthentication and authorization is successful in the registration areaat the movement destination. Note that the case in which the procedureof network slice-specific authentication and authorization is successfulmay mean a case in which the UE 10 receives EAP success. In this case,the reason value of the first reason value is canceled, and thus the UE10 may transmit, to the AMF 30, a registration request (initialregistration request, mobility registration update, or periodicregistration update) using S-NSSAI #1 associated with the combinedreason value or S-NSSAI of a serving PLMN to which S-NSSAI #1 associatedwith the combined reason value is mapped (S1603).

In the present specification, a user device (user equipment (UE)) (suchas a mobile station, a mobile terminal, a mobile device, or a wirelessdevice) is an entity connected to a network through a wirelessinterface.

A UE in the present specification is not limited to a dedicatedcommunication device but may be an optional instrument having acommunication function as a UE described in the present specification asfollows.

The terms “user terminal (user equipment (UE)) (as a term used in3GPP)”, “mobile station”, “mobile terminal”, “mobile device”, and“wireless device” are typically intended to be synonymous with eachother and may be a stand-alone mobile station such as a terminal, acellular phone, a smartphone, a tablet, a cellular IoT terminal, or aIoT device.

Note that it should be understood that the terms “UE” and “wirelessdevice” include a device at rest for a long duration.

The UE may be, for example, a production-manufacturing facility and/oran energy-related machine (such as a boiler, an engine, a turbine, asolar panel, a wind power generator, a hydraulic generator, a thermalpower generator, a nuclear power generator, a secondary battery, anuclear system, a nuclear-related instrument, a heavy electricinstrument, a pump including a vacuum pump, a compressor, a fan, an airblower, a hydraulic instrument, an air pressure instrument, a metalfabrication machine, a manipulator, a robot, a robot application system,a tool, a mold, a roll, a conveyance device, an elevation device, acargo handling device, a fiber machine, a sewing machine, a printer, aprinting-related machine, a paper work machine, a chemical machine, amine machine, a mine-related machine, a construction machine, abuilding-related machine, an agricultural machine and/or instrument, aforestry machine and/or instrument, a fishery machine and/or instrument,a safety and/or environmental conservation instrument, a tractor, abearing, a fine bearing, a chain, a gear, a power transmission device, alubrication device, a valve, a pipe joint, and/or an application systemof an optional above-described instrument or machine).

The UE may also be, for example, a transfer device (such as a vehicle,an automobile, a two-wheeled automobile, a bicycle, a train, a bus, arear car, a rickshaw, a ship or any other watercraft, an airplane, arocket, an artificial satellite, a drone, or a balloon).

The UE may also be, for example, an information communication device(such as an electronic calculator or a related device thereof, acommunication device or a related device thereof, or an electroniccomponent).

The UE may also be, for example, a refrigerator, a refrigeratorapplication product or device, a commercial or service instrument, anautomatic vending machine, an automatic service machine, an officemachine or device, a consumer electric-electronic machine instrument(such as a voice instrument, a speaker, a radio, a video instrument, atelevision, an oven microwave, a rice cooker, a coffee maker, adishwasher, a washing machine, a dryer machine, an electric fan, aventilator or a related product thereof, or a vacuum cleaner).

The UE may also be, for example, an electronic application system or anelectronic application device (such as an X-ray device, a particleacceleration device, a radioactive material application device, a soundwave application device, an electromagnetic application device, or anelectric power application device).

The UE may also be, for example, a light bulb, an illumination, ameasurement machine, an analysis instrument, a test machine, ameasurement machine (such as a smoke alarm, a personal alert sensor, amotion sensor, or a wireless tag), a chronometer (watch or clock), aphysical and chemical machine, an optical machine, a medical instrumentand/or medical system, a weapon, an amenity craft tool, or a hand tool.

The UE may also be, for example, a personal digital assistant or device(such as an electronic device (for example, a personal computer or anelectronic meter) to which a wireless card, a wireless module, or thelike is attached or inserted) having a wireless communication function.

The UE may also be, for example, a device or part thereof that providesapplications, services, and solutions as follows in “Internet of Things(IoT)” using wired and wireless communication technologies.

IoT devices (or things) include appropriate electronic devices,software, sensors, and network connections that enable data collectionand data exchange between devices and with any other communicationdevice.

An IoT device may be an automated instrument that obeys softwarecommands stored in an internal memory.

The IoT device may operate without supervision nor response by a person.The IoT device may be a device installed for a long duration and/or maybe inactive for a long duration.

The IoT device may be implemented as part of a stationary device. TheIoT device may be embedded in a non-stationary device (such as avehicle) or attached to a monitored or traced animal or person.

It should be understood that IoT technologies can be implemented on anoptional communication device connectable to a communication networkthat transmits and receives data irrespective of control based on aninput by a person nor a software command stored in a memory.

It should be understood that the IoT device is also called amachine-type communication (MTC) device, a machine-to-machine (M2M)communication device, or a narrow band-IoT (NB-IoT) UE.

It should be understood that the UE can support one or a plurality ofIoTs or MTC applications.

Examples of the MTC applications are listed in the table (refer to 3GPPTS22.368 V13.2.0 (2017 Jan. 13) Annex B, the contents of which areincorporated in the present specification by reference) below.

The list is not exhaustive but indicates MTC applications as examples.

Service range MTC application Security Monitoring system Backup of aland-line phone Physical access control (for example, access to abuilding) Vehicle/driver security Tracking & tracing Fleet managementOrder management Telematics insurance: charging in accordance with drive(Pay as you drive (PAYD)) Assets management Navigation Trafficinformation Road tolling Road traffic optimisation/steering PaymentPoint of sales (POS) Vending machines Gaming machines Health Monitoringvital signs Supporting the aged or handicapped Web access telemedicinepoints Remote diagnostics Remote Sensors maintenance/control LightingPumps Valves Elevator control Vending machine control Vehiclediagnostics Metering Power Gas Water Heating Grid control Industrialmetering Consumer devices Digital photo frame Digital camera Electronicbook

Examples of applications, services, and solutions include a mobilevirtual network operator (MVNO) service/system, a disaster-preventionwireless service/system, a private wireless phone (private branchexchange (PBX)) service/system, a PHS/digital codeless phoneservice/system, a point-of-sale (POS) system, an advertisement deliverservice/system, a multicast (multimedia broadcast and multicast service(MBMS)) service/system, a vehicle-to-everything (V2X: inter-vehicularcommunication and road-vehicle and pedestrian-vehicle communication)service/system, an in-train mobile wireless service/system, a positioninformation-related service/system, a disaster/emergency wirelesscommunication service/system, an internet-of-things (IoT)service/system, a community service/system, a video distributionservice/system, a femto cell application service/system, aVoice-over-LTE (VoLTE) service/system, a wireless TAG service/system, acharging service/system, a radio on-demand service/system, a roamingservice/system, a user behavior monitoring service/system, acommunication carrier/communication NW selection service/system, afunction restriction service/system, a proof-of-concept (PoC)service/system, a terminal-oriented private information managementservice/system, a terminal-oriented display-video service/system, aterminal-oriented non-communication service/system, and an ad hoc NW/DTN(delay tolerant networking) service/system.

Note that the above-described UE categories are merely applicationexamples of technological ideas and aspects described in the presentspecification. Various kinds of modifications may be provided by theskilled person in the art without limitations to the examples.

Note that the above-described aspects do not limit the presentdisclosure but may be modified as appropriate without departing from thescope of the present invention. The present disclosure may be achievedby combining the aspects as appropriate.

The present application invention is described above with reference tothe aspects but is not limited to the above description. Theconfigurations and details of the invention of the present applicationinclude various modifications that can be understood by the skilledperson in the art within the scope of the invention.

Although the present disclosure is explained above with reference toexample embodiments, the present disclosure is not limited to theabove-described example embodiments. Various modifications that can beunderstood by those skilled in the art can be made to the configurationand details of the present disclosure within the scope of the invention.

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2019-146563, filed on Aug. 8, 2019, theentire contents of which are incorporated herein.

REFERENCE SIGNS LIST

-   -   10 UE    -   11 COMMUNICATION UNIT    -   12 CONTROL UNIT    -   20 NG-(R)AN    -   30 AMF    -   31 COMMUNICATION UNIT    -   32 CONTROL UNIT    -   40 SMF    -   50 UPF    -   60 UDM    -   70 AAA

What is claimed is:
 1. A communication method performed by a corenetwork node, the communication method comprising: receiving, from awireless terminal, a registration request message including at least onepiece of single network slice selection assistance information(S-NSSAI); activating timers for determining whether the procedure ofnetwork slice-specific authentication and authorization (NSSAA) isabnormal or not for each a certain S-NSSAI as a target of the NSSAA;recognizing that the NSSAA for first S-NSSAI is completed as failure ina case where a timer among the timers expires, the first S-NSSAIcorresponding to the timer; and transmitting a non-access stratum (NAS)message to the wireless terminal, wherein the NAS message includesrejected NSSAI including the first S-NSSAI and a cause value, the causevalue indicates that the first S-NSSAI cannot be used due to the failureof the NSSAA, and the certain S-NSSAI is included in the at least onepiece of S-NSSAI.
 2. The communication method according to claim 1,wherein the NAS message including the rejected NSSAI including the firstS-NSSAI and the cause value is a de-registration request message.
 3. Thecommunication method according to claim 1, wherein the NAS messageincluding the rejected NSSAI including the first S-NSSAI and the causevalue is a configuration update command message.
 4. The communicationmethod according to claim 1, further comprising transmitting, to thewireless terminal, a registration accept message including the certainS-NSSAI associated with a pending status, wherein the pending statusindicates that the NSSAA for the certain S-NSSAI is performed.
 5. Thecommunication method according to claim 4, wherein the NSSAA for thecertain S-NSSAI is executed after the registration accept message istransmitted.
 6. The communication method according to claim 4, whereinthe registration accept message includes empty allowed NSSAI when the atleast one piece of S-NSSAI included in requested NSSAI is eachcontinuously a target of the NSSAA.
 7. (canceled)
 8. The communicationmethod according to claim 1, further comprising storing a status of theNSSAA for the certain S-NSSAI in a UE context of the wireless terminal,wherein the status of the NSSAA for the certain S-NSSAI is any of“success”, “failure”, and “pending”.
 9. The communication methodaccording to claim 1, wherein the NAS message including the rejectedNSSAI including the first S-NSSAI and the cause value is a registrationaccept message, and the registration accept message is transmitted basedon the first S-NSSAI included in requested NSSAI transmitted to anothercore network node by the wireless terminal, after the NSSAA for thefirst S-NSSAI by the other core network node is completed as failure.10. A communication method performed by a wireless terminal, thecommunication method comprising: transmitting, to a core network node, aregistration request message including at least one piece of singlenetwork slice selection assistance information (S-NSSAI); and receivinga non-access stratum (NAS) message from the core network node afternetwork slice-specific authentication and authorization (NSSAA) forfirst S-NSSAI corresponding to a timer based on the timer among timersfor determining whether the procedure of the NSSAA activated for each acertain S-NSSAI as a target of the NSSAA is abnormal or not is completedas failure, wherein the NAS message includes rejected NSSAI includingthe first S-NSSAI and a cause value, the cause value indicates that thefirst S-NSSAI cannot be used due to the failure of the NSSAA, and thecertain S-NSSAI is included in the at least one piece of S-NSSAI. 11.The communication method according to claim 10, wherein the NAS messageincluding the rejected NSSAI including the first S-NSSAI and the causevalue is a de-registration request message.
 12. The communication methodaccording to claim 10, wherein the NAS message including the rejectedNSSAI including the first S-NSSAI and the cause value is a configurationupdate command message.
 13. The communication method according to claim10, further comprising receiving, from the core network node, aregistration accept message including the certain S-NSSAI associatedwith a pending status, wherein the pending status indicates that theNSSAA for the certain S-NSSAI is performed.
 14. The communication methodaccording to claim 13, wherein the NSSAA for the certain S-NSSAI isexecuted after the registration accept message is received.
 15. Thecommunication method according to claim 13, wherein the registrationaccept message includes empty allowed NSSAI when the at least one pieceof S-NSSAI included in requested NSSAI is each continuously a target ofthe NSSAA.
 16. (canceled)
 17. The communication method according toclaim 10, further comprising storing a status of the NSSAA for thecertain S-NSSAI in a UE context of the wireless terminal, wherein thestatus of the NSSAA for the certain S-NSSAI is any of “success”,“failure”, and “pending”.
 18. The communication method according toclaim 10, further comprising: storing rejected NSSAI including the firstS-NSSAI and the cause value; and not using the first S-NSSAI included inthe stored requested NSSAI until the wireless terminal is powered off ora UICC including a USIM is removed.
 19. The communication methodaccording to claim 10, wherein the NAS message including the rejectedNSSAI including the first S-NSSAI and the cause value is a registrationaccept message, and the registration accept message is received based onthe first S-NSSAI included in requested NSSAI transmitted to anothercore network node by the wireless terminal, after the NSSAA for thefirst S-NSSAI by the other core network node is completed as failure.20. A core network node comprising: at least one memory storinginstructions, and at least one processor configured to execute theinstructions to; receive, from a wireless terminal, a registrationrequest message including at least one piece of single network sliceselection assistance information (S-NSSAI); activate timers fordetermining whether the procedure of network slice-specificauthentication and authorization (NSSAA) is abnormal or not for each acertain S-NSSAI as a target of the NSSAA; recognize that the NSSAA forfirst S-NSSAI is completed as failure in a case where a timer among thetimers expires, the first S-NSSAI corresponding to the timer; andtransmit a non-access stratum (NAS) message to the wireless terminal,wherein the NAS message includes rejected NSSAI including the firstS-NSSAI and a cause value, the cause value indicates that the firstS-NSSAI cannot be used due to the failure of the NSSAA, and the certainS-NSSAI is included in the at least one piece of S-NSSAI.
 21. A wirelessterminal comprising: at least one memory storing instructions, and atleast one processor configured to execute the instructions to; transmit,to a core network node, a registration request message including atleast one piece of single network slice selection assistance information(S-NSSAI); and receive a non-access stratum (NAS) message from the corenetwork node after network slice-specific authentication andauthorization (NSSAA) for first S-NSSAI corresponding to a timer basedon the timer among timers for determining whether the procedure of theNSSAA activated for each S-NSSAI as a target of the NSSAA is abnormal ornot is completed as failure, wherein the NAS message includes rejectedNSSAI including the first S-NSSAI and a cause value, the cause valueindicates that the first S-NSSAI cannot be used due to the failure ofthe NSSAA, and the certain S-NSSAI is included in the at least one pieceof S-NSSAI.